On the third Monday of every January, the United States celebrates the birthday of Martin Luther King Jr., the iconic Baptist minister and activist who became one of the best-known leaders of the Civil Rights Movement. The first federal Martin Luther King Jr. holiday was celebrated in 1986, though President Ronald Reagan signed the law in November 1983. It took more than a decade for all fifty states to recognize it, in 2000.
Image: Martin Luther King Jr., March 26, 1964. Photograph by Marion S. Trikosko. (Library of Congress)