A grandfather clause is a provision in which an old rule continues to apply to some existing situations, while a new rule will apply to all future cases. Frequently, the exemption is limited; it may extend for a set period of time, or it may be lost under certain circumstances. For example, a "grandfathered power plant" might be exempt from new, more restrictive pollution laws, but those rules would not apply if the plant were expanded. Often, such a provision is used as a compromise or out of practicality, to effect new rules without upsetting a well-established logistical or political situation. This extends the idea of a rule not being retroactively applied.
The concept originated in late nineteenth-century legislation and constitutional amendments passed by a number of U.S. Southern states, which created new literacy and property restrictions on voting, but exempted those whose ancestors (grandfathers) had the right to vote before the Civil War. The intent and effect of such rules was to prevent poor and illiterate African American former slaves and their descendants from voting, but without denying poor and illiterate whites the right to vote. Although these original grandfather clauses were eventually ruled unconstitutional, the terms grandfather clause and grandfather remain in use, with no connotation regarding the justness of these provisions when applied in other areas.
The original grandfather clauses were contained in new state constitutions and Jim Crow laws passed from 1890 to 1910 in many of the Southern United States to prevent blacks, Mexican Americans (in Texas), and certain whites from voting. Prohibitions on freedmen's voting in place before 1870 were nullified by the Fifteenth Amendment.
After conservative white Democrats took control of state legislatures again after the Compromise of 1877, they began to work to restrict the ability of blacks to vote. Paramilitary groups such as the Ku Klux Klan had intimidated blacks or barred them from the polls in numerous elections before the Redemption. The coalition of Populists and Republicans in fusion tickets in the 1890s threatened Democratic control and increased the Democrats' desire to restrict blacks from voting. Conservative whites developed statutes and passed new constitutions creating restrictive voter registration rules. Examples included imposition of poll taxes and residency and literacy tests. An exemption to such requirements was made for all persons allowed to vote before the American Civil War, and any of their descendants. The term grandfather clause arose from the fact that the laws tied the then-current generation's voting rights to those of their grandfathers. According to Black's Law Dictionary, some Southern states adopted constitutional provisions exempting from the literacy requirements descendants of those who fought in the army or navy of the United States or of the Confederate States during a time of war.
After the U.S. Supreme Court found such provisions unconstitutional in Guinn v. United States (1915), states were forced to stop using the grandfather clauses to provide exemption to literacy tests. Without the grandfather clauses, tens of thousands of poor Southern whites were disfranchised in the early 20th century. As decades passed, Southern states tended to expand the franchise for poor whites, but most blacks could not vote until after passage of the 1965 Voting Rights Act. Ratification in 1964 of the Twenty-fourth Amendment to the United States Constitution prohibited the use of poll taxes in federal elections, but some states continued to use them in state elections.
The 1965 Voting Rights Act had provisions to protect voter registration and access to elections, with federal enforcement and supervision where necessary. In 1966, the Supreme Court ruled in Harper v. Virginia Board of Elections that poll taxes could not be used in any elections. This secured the franchise for most citizens, and voter registration and turnout climbed dramatically in Southern states.
In spite of its origins, today the term grandfather clause does not retain any pejorative sense.
Modern examples 
- The United States Constitution appears on a cursory reading to stipulate that presidential candidates must be natural born citizens of the U.S.A. However, there is a further category of persons eligible for that office, now exhausted: those who were citizens of the U.S.A. at the time of the adoption of that constitution. Without that provision, it would have required a strained reading to construe that all actual presidents born in the colonial period were born in the U.S.A., because the United States did not exist prior to July 4, 1776, the date on which the Declaration of Independence was adopted, and Alexander Hamilton (who did not ever actually run for the office, but was considered presidential material by some) would have been barred because of his birth in the West Indies.
- In 1949, standards were passed requiring certain fire-safety improvements in schools. However, older schools, such as the Our Lady of the Angels School in Illinois, were not required to be retrofitted to meet the requirements, leading to the deadly Our Lady of the Angels school fire in which 92 students and 3 teachers died.
- In 1952, the United States ratified the Twenty-second Amendment to the United States Constitution, preventing presidents from running for a third term (or a second term, if they had served more than two years of another's term). The text of the amendment specifically excluded the sitting president from its provisions, thus making Harry Truman eligible to run for president in 1952 – and, theoretically, for every subsequent presidential election thereafter – even though he had served a full term and almost four years of a previous president's term. Truman did not take advantage of this provision, however, and chose not to stand for election again.
- In the 1980s, as states in America were increasing the permitted age of drinking to 21 years, many people who were under 21 but of legal drinking age before the change were still permitted to purchase and drink alcoholic beverages. Similar conditions applied when New Jersey and certain counties in New York raised tobacco purchase ages from 18 to 19 years in the early 2000s.
- In 2012, Macau increased the permitted age of entering casinos to 21. However, casino employees between the ages of 18 and 21 before the change were still permitted to enter their places of employment.
- During the Federal Assault Weapons Ban, certain firearms made before the ban's enactment were legal to own. Automatic weapons that were manufactured and registered before the Firearm Owners Protection Act (enacted May 19, 1986) may legally be transferred to civilians.
- According to the Interstate Highway Act, private businesses are not allowed at rest areas along interstates. However, private businesses that began operations before January 1, 1960, were allowed to continue operation indefinitely.
- Michigan law MI ST 287.1101-1123 forbade ownership or acquisition of large and dangerous exotic carnivores as pets. But animals already owned as pets at the time of enactment were grandfathered in, and permitted to be kept.
- The FCC stated that, as of March 1, 2007, all televisions must be equipped with digital tuners, but stores that had TV sets with analog tuners only could continue to sell analog-tuner TV sets.
- In 1967, the FCC prohibited companies from owning both a radio and a television station in the same marketing area, but those already owned before the ruling were permanently grandfathered. For example, ABC already owned WABC-TV, 77 WABC and WABC-FM (now WPLJ), and so could continue to own all three stations after the law was passed. But then-current broadcasting companies that had a radio station in a city could not acquire an adjacent television station, and companies that owned a television station in a city could not acquire adjacent radio stations. In 1996, the law was overturned. Companies can now own up to eight radio stations and two television stations in a market, provided that they do not receive more than 33% of its advertising revenues.
- In 1984 Mississippi passed a law changing their official mode of capital punishment from the gas chamber to lethal injection. Under the new law, anyone sentenced after July 1, 1984, was to be executed by lethal injection; those condemned before that date were “grandfathered” into the gas chamber. Therefore, three more convicted murderers would die in the chamber – Edward Earl Johnson and Connie Ray Evans in 1987, and Leo Edwards in 1989. In 1998, the Mississippi Legislature changed the execution law to allow all death row inmates to be executed by lethal injection.
- In 1965, the Canadian government under Prime Minister Lester B. Pearson passed legislation that required senators to retire when they reached the age of 75. However, senators appointed before the legislation was passed were exempted from the mandatory retirement rule.
- During Canada's federal Redistribution, a Grandfather Clause ensures that no Province can have fewer seats after Redistribution than it did in 1985 
Standards compliance 
- Strict building codes to withstand frequent seismic activity were implemented in Japan in 1981. These codes applied only to new buildings, and existing buildings were not required to upgrade to meet the codes. One result of this was that during the great Kobe earthquake, many of the pre-1981 buildings were destroyed or written off, whereas most buildings built post-1981, in accordance with the new building codes, withstood the earthquake without structural damage.
- Wigwag-style railroad crossing signals were deemed inadequate in 1949 and new installations were banned in the United States. Existing wigwag signals were allowed to remain and 60 years later, there are still about 50 wigwag signals in use on railroads in the USA.
- The UK's national rail network Network Rail requires new locomotives and rolling stock to pass tests for Electromagnetic compatibility (EMC) to ensure that they do not interfere with signalling equipment. Some old diesel locomotives, which have been in service for many years without causing such interference, are exempted from EMC tests and are said to have acquired grandfather rights.
- The Steel Electric-class ferryboats used by Washington State Ferries were in violation of several Coast Guard regulations, but because they were built in 1927, before the enactment of the regulations, they were allowed to sail. Those ferries were decommissioned in 2008.
- Tolled highways that existed before the Interstate Highway System are exempt from Interstate standards despite being designated as Interstate highways. Many such toll roads (particularly the Pennsylvania Turnpike) remain as such. However, tolled highways built since the Interstate system, such as the tolled section of PA Route 60 and PA Turnpike 576, must be built or upgraded to Interstate standards before receiving Interstate designation. Both highways are to be part of the Interstate system, with PA 60 now I-376 and PA Turnpike 576 to become I-576 in the near future. As well, U.S. Interstate Highway standards mandate a minimum 11-foot median; however, highways built before those standards have been grandfathered into the system. The Kansas Turnpike is the most notable example, as it has been retrofitted with a Jersey barrier along its entire 236-mile length.
- The earliest Ontario 400-series highways and other expressways do not meet current standards, however it would be prohibitively expensive to immediately rebuild them all to updated guidelines, unless a reconstruction is warranted by safety concerns and traffic levels. As a result, substandard sections of freeways such as low overpasses and short acceleration/de-acceleration lanes are often retrofitted with guard rail, warning signage, lower speed limits, or lighting.
- The United States Federal Communications Commission has required all radio stations licensed in the United States since the 1930s to have four-letter call signs starting with a W (for stations east of the Mississippi River) or a K (for stations west of the Mississippi River). But stations with three-letter call signs and stations west of the Mississippi River starting with a W and east of the Mississippi River starting with a K – such as WRR in Dallas and WHB in Kansas City, plus KQV and KYW in Pennsylvania, all licensed before the 1930s – have been permitted to keep their call signs. In the western United States, KOA in Denver, Colorado, KGA in Spokane, Washington, KEX in Portland, Oregon, and KHJ and KFI in Los Angeles, California, among many others, have been permitted to keep their original or reassigned three-letter call signs.
- In aviation, grandfather rights refers to the control that airlines exert over “slots” (that is, times alloted for access to runways). While the trend in airport management has been to reassert control over these slots, many airlines are able to retain their traditional rights based on current licences.
- In the UK, until 1992, holders of ordinary car driving licences were allowed to drive buses and coaches of any size, provided that the use was not commercial and that there was no element of "hire or reward" in the vehicles' use; in other words, no one was paying to be carried. The law was changed in 1992 so that drivers had to hold a PCV (PSV) licence, but anyone who had driven buses before 1992 under the old rules was given grandfather rights to carry on doing so.
- Some MOT test standards in UK do not apply to vehicles first registered prior to the implementation of the legislation that introduced them. For example, vehicles first registered prior to 1 January 1973 are exempt from the requirement to use retro-reflective Yellow/White vehicle registration plates and vehicles first registered prior to 1 January 1965 are exempt from Seat Belt standards/legislation unless they have been retrospectively fitted.
- Some U.S. states which conduct their inspection/maintenance (I/M) programs for motor vehicle emission testing that have a rolling chassis exemption e.g. a motor vehicle model 25 years old are exempted from emission tests.
- The National Football League (NFL) currently prohibits corporate ownership of teams. Ownership groups can have no more than 24 members, and at least one partner must hold a 30% ownership stake. The league has exempted the Green Bay Packers from this rule; the team has been owned by a publicly owned, nonprofit corporation since 1923, decades before the league's current ownership rules were put in place.
- Beginning in 1979, the National Hockey League required all players to wear helmets. But if a player had signed his first professional contract before this ruling, he was allowed to play without a helmet. Craig MacTavish was the last player to do so, playing without a helmet up until his retirement in 1997, other notable players include Guy Lafleur and Rod Langway who retired in 1991 and 1993, respectively. Kerry Fraser was the last referee who was not required to wear a helmet, until the ratification of the new NHL Officials Association collective bargaining agreement on March 21, 2006. Some have speculated that if the NHL makes visors mandatory, older players will be exempt.
- Three former venues in the National Hockey League – Chicago Stadium, Boston Garden and Buffalo Memorial Auditorium – had shorter-than-regulation ice surface, as their construction predated the regulation. The distance was taken out of the neutral zone and this often threw visiting players off of their game, giving home teams an immense advantage. Many fans believed this advantage allowed Bobby Orr to complete his famous end-to-end rushes more quickly in the Garden. All three arenas were replaced by newer facilities in 1996. The regulation does not apply in many minor league venues, and in older minor league venues shorter than regulation, the distance was taken from neutral zones.
- In 2006, NASCAR passed a rule that required teams to field no more than four cars. Since Roush Racing had five cars, they could continue to field five cars until the end of 2009.
- In 1997, to honor Jackie Robinson, Major League Baseball prohibited all teams from issuing #42 in the future; current players wearing #42 were allowed to continue to do so. As of 2013[update], New York Yankees' closer Mariano Rivera is the only player still wearing #42. However, since 2009, all players are required to wear #42 (without names) on Jackie Robinson Day.
- In 1920, when Major League Baseball introduced the prohibition of the spitball, the league recognized that some professional pitchers had nearly built their careers on using the spitball. The league made an exception for 17 named players, who were permitted to throw spitballs for the rest of their careers. Burleigh Grimes threw the last legal spitball in 1934.
- The NFL outlawed the one-bar facemask for the 2004 season but allowed existing users to continue to wear them. Scott Player was the last player to wear the one-bar facemask.
- The NFL introduced a numbering system for the 1973 season, requiring players to be numbered by position. Players who played in the NFL in 1972 and earlier were allowed to keep their old numbers, although New York Giants linebacker Brad Van Pelt wore number 10 despite entering the league in 1973 (Linebackers had to be numbered in the 50s at the time; since 1984 they may now wear numbers in the 50s or 90s. Van Pelt got away with it because he was the team's backup kicker his rookie season). The last player to be covered by the grandfather clause was Julius Adams, a defensive end (1971–1985, 1987) for the New England Patriots, who wore number 85 through the 1985 season. He wore a different number during a brief return two years later.
- Major League Baseball rule 1.16 requires players who were not in the major leagues before 1983 to wear a batting helmet with at least one earflap. The last player to wear a flapless helmet was the Florida Marlins' Tim Raines in 2002 (career began in 1979). The last player eligible to do so was Julio Franco in 2007 (career began in 1982), although he opted to use the flapped version.
- For many decades, American League (AL) umpires working behind home plate used large, balloon-style chest protectors worn outside the shirt or coat, while their counterparts in the National League wore chest protectors inside the shirt or coat, more akin to those worn by catchers. In 1977, the AL ruled that all umpires entering the league had to wear the inside protector, although umpires already in the league who were using the outside protector could continue to do so. The last umpire to regularly wear the outside protector was Jerry Neudecker, who retired after the 1985 season. (Since 2000, Major League Baseball has used the same umpire crews for both leagues.)
- The National Hot Rod Association is enforcing a grandfather clause banning energy drink sponsors from entering the sport if they were not sponsoring cars as of April 24, 2008, pursuant to the five-year extension of its sponsorship with Coca-Cola, which is changing the title sponsorship from Powerade to Full Throttle Energy Drink.
- Even though tobacco advertising in car racing was banned, the Marlboro cigarette brand, owned by Philip Morris USA in the U.S., British American Tobacco in Canada, and Philip Morris International elsewhere, is grandfathered in to sponsoring a car in the F1 series on the agreement that the name is not shown in places that banned it.
- NASCAR allows some grandfathered sponsorships by telecommunications companies in the top-level Sprint Cup and insurance companies in the second-level Nationwide Series, while rules forbid new sponsors in these categories.
See also 
- Ex post facto
- Generally recognized as safe
- Generally recognized as safe and effective
- Grace period
- Nonconforming use
- Sunset provision
- Williams v. Mississippi
- "Grandfather clause". Concise Encyclopædia Britannica. Retrieved 2009-09-06.
- Glenn Feldman, The Disfranchisement Myth: Poor Whites and Suffrage Restriction in Alabama, Auburn: University of Georgia Press, 2004, p.136
- "Michigan State University College of Law". Animallaw.info. Retrieved 2009-09-06.
- "Reforming the Senate". CBC News. 2008-12-30. Retrieved 2010-12-21.
- "Edmonton Oilers Heritage Website - Craig MacTavish". Oilersheritage.com. Retrieved 2009-09-06.
- By Bryan Hoch / MLB.com. "Rivera 'blessed' to wear No. 42 | MLB.com: News". Mlb.mlb.com. Retrieved 2009-09-06.
- Press, Associated (2009-02-18). "Former Giants linebacker Brad Van Pelt dies". News.bostonherald.com. Retrieved 2009-09-06.
Further reading 
- Riser, R. Volney (2006). "Disfranchisement, the U.S. Constitution, and the Federal Courts: Alabama's 1901 Constitutional Convention Debates the Grandfather Clause". American Journal of Legal History 48 (3): 237–279. JSTOR 25434804.
- Grandfather Clause in From Jim Crow to Civil Rights: The Supreme Court and the Struggle for Racial Equality