Monday, January 15 marks the 21st year that Martin Luther King, Jr.’s birthday has been celebrated as a federal holiday on the third Monday in January. (It also falls on Dr. King’s actual birthday this year.) President Ronald Reagan signed the bill recognizing the holiday on November 2, 1983 and it was first observed on January 20, 1986.
According to Wikipedia, the holiday was first proposed after Dr. King’s death by trade unions. After Jimmy Carter was elected in 1976 with the help of unions, he endorsed the holiday, as well. The King Center then turned to the public and corporate America to lobby for the holiday. The strategy worked, particularly after Stevie Wonder released the single "Happy Birthday" in 1980 to publicize the campaign, and six million signatures were collected and sent to Congress endorsing a special day to honor Dr. King.
There was opposition to the holiday, in particular from Senator Jesse Helms. President Ronald Reagan initially opposed MLK Day, but backed down after the bill to establish the holiday passed 338 to 90 in the U.S. House of Representatives and 78 to 22 in the U.S. Senate. Check out:
The Autobiography of Martin Luther King, Jr. by Martin Luther King, Jr.
At Canaan’s Edge: America in the King Years by Taylor Branch.
In Remembrance of Martin by Idanha Films. (DVD)
Ring Out Freedom: The Voice of Martin Luther King and the Making of the Civil Rights Movement by Fredrik Sunnemark.
Growing Up King: An Intimate Memoir by Dexter Scott King.