Southern Democrats walked out at the party 's national convention in Philadelphia because of Truman 's endorsement of civil rights for African Americans , and Mississippi , the state with the highest proportion of blacks in its population , was alongside neighbouring Alabama the most committed to an immediate bolt . Indeed , whereas only half of Alabama 's delegation walked out , '' all '' of Mississippi 's did
party 's national convention in Philadelphia
1948 Democratic National Convention
1948 United States presidential election in Mississippi