The major event Martin Luther King Jr. led in Washington, D.C. in 1963 is the "March on Washington for Jobs and Freedom." This historic gathering attracted over 250,000 participants and became a pivotal moment in the Civil Rights Movement. It was during this event that King delivered his iconic "I Have a Dream" speech, which articulated the demand for racial equality and economic justice. The march not only highlighted the prevailing racial injustices in the United States but also galvanized public support for the civil rights legislation that followed.