The significant U.S. law passed in 1965 to prohibit racial discrimination in voting is the Voting Rights Act. This landmark legislation aimed to eliminate barriers that systematically disenfranchised African Americans, particularly in Southern states. Motivated by the Civil Rights Movement and the violent suppression of black voters, the Act was designed to ensure that all citizens had the right to vote, addressing practices like literacy tests and poll taxes. It also authorized federal oversight of voter registration in areas with a history of discrimination. The Voting Rights Act is crucial in expanding civil rights and ensuring greater electoral participation for marginalized communities in the United States.