Americans are honoring the memory of civil rights icon Martin Luther King Jr. on Monday with a federal holiday marking his birthday.

King was a Baptist preacher who fought discrimination and racism in the 1950s and 1960s, mainly in the southern United States, where blacks were subjected to unequal treatment in society and at times the target of violence.

King, an advocate for non-violent protests, was assassinated in 1968 at the age of 39. There is now a monument in his honor in Washington.

King gained prominence after leading a successful protest against segregation on the buses in Montgomery, Alabama. Under that system, blacks were required to sit in the back of the bus and, if the vehicle was full, they had to give up their seats to white people.

The landmark Civil Rights Act of 1964 made segregation illegal. That same year King won the Nobel Peace Prize.