The scene where the shyster politician tells the negroes they will get 40 acres and a mule for voting the way their friends do. Is this the genesis of the democratic lock on the black vote?
Don't call them negroes.
As for your question, the shift of the african american vote to the democrats has multiple sources. 1. During the great migration of african americans to the north. 2. During the 1950's-70's as the Republican party began to woo the South (Nixon really was the first to do so with great success) and the democrats began to move into urban areas throughout the country but especially the Northeast.
But short answer, no the democrats had very little to no influence over the african american vote during the 19th century.