Soon afterwards, Bell took a position as an assistant counsel for the NAACP Legal Defense and Educational Fund (LDF), crafting legal strategies at the forefront of the battle to undo racist laws and segregation in schools. At the LDF, he worked alongside other prominent civil-rights attorneys such as Thurgood Marshall, Robert L. Carter and Constance Baker Motley. Bell was assigned to Mississippi. While working at the LDF, Bell supervised more than 300 school desegregation cases and spearheaded the fight of James Meredith to secure admission to the University of Mississippi, over the protests of governor Ross Barnett.