45% of employers give workers Martin Luther King Jr. Day off—here's how it became a holiday

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Civil rights leader Reverend Martin Luther King, Jr. delivers a speech to a crowd on October 16, 1965 in New York City, New York.

If you're one of the lucky ones kicking back this coming Monday with an extra paid day off, you've got labor unions, Stevie Wonder, a persistent congressman and the largest petition in U.S. history to thank.

Almost half, 45 percent, of American employers will close on Monday, Jan. 21 to honor the legacy and 90th birthday of Martin Luther King, Jr., according to a yearly survey from Bloomberg Law. That's more than offer holidays for Columbus Day or George Washington's Birthday (also commonly referred to as Presidents Day.)

The popularity of the federal holiday has grown in recent years, but as recently as 2009, only 28 percent of employers gave the day off, according to Bloomberg Law.

Up until 1986, the vast majority of workers wouldn't have had the day off. The third Monday in January was only designated a federal holiday to honor Martin Luther King Jr., born Jan. 15, in 1983, following an uphill battle lasting 15 years — and it wasn't observed for the first time until three years later.

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Marchers carry signs through downtown Memphis during the annual Martin Luther King Day march in Memphis, Tenn.

The initial call for a holiday in honor of the civil rights leader came from union leaders as a part of contract negotiations, though Representative John Conyers first introduced a bill in Congress to make the leader's birthday a national holiday shortly after King's death in 1968.

The bill would likely have died in Congress were it not for the persistence of the King Center and union members in various industries across the country, who advocated strongly for the holiday. Many unions also held strikes until provisions were including in their contracts that stipulated King's birthday would be a paid day off, according to The Nation.

When Conyers' bill, which he reintroduced in Congress numerous times, did come up for a vote in the House in 1979, it fell five votes short of passing, despite then-President Jimmy Carter's endorsement. Opponents argued that awarding the day off would be costly, and that a federal holiday honoring a private citizen was contrary to tradition.

Since 1968, the King Center had been calling upon supporters, policy officials, union leaders and corporations to back workers taking the day off, eventually launching a campaign to generate public support for MLK Day that resulted in Stevie Wonder dedicating his hit song "Happy Birthday" to King in 1980. That led to large donations from corporations like Coca-Cola and Miller Brewing Company in 1982.

The final push came when the King Center collected 6 million signatures in favor of an MLK Day bill, "the largest petition in favor of an issue in U.S. history," according to The Nation.

All of these efforts led up to Nov. 2, 1983, when then-President Ronald Reagan signed a bill creating a federal holiday in King's honor. Though Reagan had originally opposed the holiday for cost reasons, it passed in the House with a veto-proof margin.

Martin Luther King Jr. Day was then finally observed as a national holiday for the first time on Jan. 20, 1986.

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