Final answer:
Martin Luther King Jr. Day became a federal holiday on November 2, 1983, and was first observed on January 20, 1986, marking Dr. King's influence on the advancement of civil rights.
Step-by-step explanation:
Martin Luther King Jr. Day became a federal holiday on November 2, 1983, when President Ronald Reagan signed the bill into law. The first observance of the holiday took place on January 20, 1986.
The establishment of this holiday was a testament to Dr. King's enduring impact on the civil rights movement, particularly through momentous events such as the Montgomery Bus Boycott of 1956, the March on Washington for Jobs and Freedom in 1963, where he delivered his iconic "I Have a Dream" speech, and his influence on the passage of the Civil Rights Act of 1964.