Your entire point is that it was wrong for Republicans to agree to withdraw federal troops from the South in 1877. Troops are controlled by the President; Congress has oversight, but not control. You’re saying you would have preferred a Democratic President in 1877 control federal troops in the South rather than having troops withdrawn. Really? You bring up Republicans still controlling Congress in 1877 as if it mattered; it didn’t. The President controls troops. In Constitutional Law (I am a lawyer), control of military forces is one of the areas that a President has the most discretion; the other is foreign affairs. Again, your point that Republicans still controlled Congress is irrelevant. Apparently you prefer Democrats to have controlled federal troops in the South during Reconstruction. Weird. It seems entirely possible that it would have been ---worse--- for African Americans to have a Democrat controlled federal troops stay in the South after 1877 than for troops to have withdrawn