1955 Alabama was represented by 2 Democrats in the Senate and 9 Democrats in the House. No Republicans on the list.
How do you think they voted for the Civil Rights Act of 1957?
Maybe they did better on the Civil Rights Act of 1964, which is what made employment discrimination illegal on a federal level?
Both passed with overwhelming Republican support; much more so than the Democrats of the time.
I'm okay with the modern Democratic party and I think that the modern Republican party is a freak show, but it's outright foolish to pretend like the Republicans of times past were the ones holding back civil rights.