In 1983, about 20 years after King's "I Have a Dream" speech, legislation for a Martin Luther King Jr. Day on the third Monday of January cleared Congress and President Ronald Reagan signed it

The holiday falls on the third Monday of January. A bill to make Martin Luther King Jr. Day a federal holiday was introduced on April 8, 1968 — four days after King was assassinated, according to the National Museum of African American History and Culture.

Martin Luther King Jr. Day, the federal holiday that honors the legacy of the American civil rights icon, is this month. Here's what you should know.