The Voting Rights Act — the landmark civil rights legislation that prohibits racial discrimination in voting — turns 50 today. Signed by President Lyndon Johnson, the law was an important victory in the campaign to overthrow the odious Jim Crow system that prevented many blacks from voting in the South.

The ratification of the 15th Amendment in 1870 extended voting rights to former slaves. Other laws — known collectively as the Enforcement Acts — were enacted that further reinforced the right of black Americans to have an equal voice in our nation’s political debates.