November 2
On November 2, 1983, President Ronald Reagan signed a bill in the White House Rose Garden that declared Martin Luther King Day a federal holiday.
MLK Day was first observed on January 20, 1986. Despite it being declared a federal holiday, Martin Luther King Day wasn’t observed by all 50 states until 2000.
Sources
A&E Television Networks. (n.d.). MLK Federal Holiday declared | November 2, 1983. History.com. https://www.history.com/this-day-in-history/mlk-federal-holiday-declared