Americans celebrate Martin Luther King Day (MLK) on the third Monday in January.
Dr. King was born in Atlanta in 1929, and became one of the USA´s most famous campaigners for civil rights and racial equality. He won the Nobel Peace Prize in 1964 and was assassinated in 1968.
(from MacMillam´s map, 2014)
More info. from the internet:
When is his birthday?
Which date was he assassinated? Where? Why?
The Washington Post today, summarizing who he was.