Air traffic controllers have one of the most important yet difficult jobs in the world: They maintain order and the flow of air traffic, safely guiding planes across the tarmac and issuing instructions about where and when they should take off or land. Prior to 1981, air traffic controllers were represented by a union known as the Professional Air Traffic Controllers Organization (PATCO), which was founded in 1968.

As government employees of the Federal Aviation Administration (FAA), air traffic controllers were legally forbidden from going on strike thanks to 1947’s Taft-Hartley Act, but PATCO still organized protests of unfair policies. In fact, PATCO led a protest in 1970 where over 2,000 of its members called out sick rather than directly going on strike; as a result, the government addressed several demands by air traffic controllers to raise pay, hire new air traffic controllers to prevent existing employees from being overworked and burning out, and so on.

PATCO continued to advocate for its employees throughout the 1970s, but since it did not enjoy a fruitful relationship with the administration of President Jimmy Carter, the union went so far as to endorse Carter’s opponent, Republican Ronald Reagan, in the 1980 presidential election. At first, Reagan—who had served as the head of a union as former president of the Screen Actors Guild (SAG)—supported PATCO’s efforts for improved pay and conditions from the campaign trail, which emboldened the union to finally go on strike once he became president.

On August 3, 1981, PATCO’s 13,000 members went on strike in pursuit of a 32 hour workweek (in the form of a four-day week consisting of eight-hour days) as well as better pay and working conditions. The strike was widely felt across the country, and over 7,000 flights were cancelled as a result.

Reagan responded quickly by invoking the Taft-Hartley Act, which made it illegal for government employees to strike, and ordering the strikers back to work. Only 1,300 left the picket lines and returned to work, so Reagan issued an ultimatum that he would fire any striker who did not go back to work within 48 hours. Two days later, on August 5, Reagan proved that his threat was not an idle one as he fired the remaining 11,359 PATCO members who were on strike, and he instituted a lifetime ban on PATCO members being rehired by the FAA (which would later be reversed by President Bill Clinton). In doing so, Reagan ended the strike in a decisive victory for the government.