After completing his term as court clerk Vann settled in Birmingham and joined the law firm of White, Bradley, Arant, All and Rose.

In 1963 Vann helped organize a referendum that changed Birmingham's form of government from a three-member commission to a mayor and nine-member council.

Vann was elected mayor of Birmingham in 1975 and served one term, losing his bid for reelection to Richard Arrington, Jr.

In 1980 Vann became a lobbyist and special counsel to Arrington, and served two terms as chair of the Birmingham Water Works and Sewer Board.

Vann was active in civic organizations and was a founding board member of the Birmingham Civil Rights Institute.