 After serving two years in the United States Army, Weltner practiced law in Atlanta and worked to defeat Georgia's county-unit system and preserve the public school system after state leaders threatened to close the schools rather than integrate.In 1962, Weltner was elected to represent Georgia's 5th congressional district in the House of Representatives as a Democrat.He was the only member of the state's congressional delegation (and the only Democrat from the Deep South) to vote for the Civil Rights Act of 1964, commenting that "We must not remain forever bound to another lost cause."