[SamAdams76]

The Republicans gained them the right to vote and they rewarded them by voting Democrat for the next 100+ years.

[BroJoeK]

Sam Adams76: "The Republicans gained them the right to vote and they rewarded them by voting Democrat for the next 100+ years."

In fact, for the first 60 years -- from 1868 until 1928, most blacks voted Republican.
Then, beginning with Franklin Roosevelt in 1932, most Northern blacks changed over to Democrats.
Still, about 1/3 of blacks voted Republican up until the election of 1964, when Lyndon Johnson's "Great Society" and Barry Goldwater's Conservative Conscience drove 95% of blacks to the Democrats, where they have remained ever since.