Doy Gorton grew up deep in “ the most Southern place on earth ”: the Mississippi Delta.

He was a child of privilege, attending segregated schools and escorting debutantes to the Old South ball wearing a Confederate uniform and sporting a sword. At the University of Mississippi in 1961, he pledged the fraternity founded by Robert E. Lee, which was fitting, as men on both sides of Mr. Gorton’s family fought for the South during the Civil War.

But the old order, which Mr. Gorton described as “based on legal white supremacy” and the plantation system, was collapsing. In 1962, James Meredith became the first African-American student to register at the University of Mississippi, and Mr. Gorton began organizing protests and events against segregation at school .