The civil rights leader known for his "I Have a Dream" speech is Martin Luther King Jr.. Delivered during the 1963 March on Washington, the speech articulated his vision of a racially integrated and harmonious America. King emphasized themes of equality, freedom, and justice, urging an end to racial discrimination. This landmark address became a pivotal moment in the civil rights movement, inspiring generations to advocate for civil liberties and spearheading legislative changes towards racial equality in the U.S.