I found this looking up for information on black conservatives on Wikipedia. Then I found Black Populism. I never heard of this movement until now. This was the last great political resistance of black Americans in the south until the Civil Rights movement of the 1950s and 1960s. It lasted roughly a decade from 1886 to 1889. The wikipedia article lists what they were able to accomplish...
-Establishing farming exchanges
-Raising money for schools
-Lobbying for better legislation
-Mounting boycotts against agricultural trusts
-Carrying out strikes for better wages
-Protesting the convict-lease system and lynching
-Demanding Black jurors in cases involving black defendants
-Promoting local political reforms and federal supervision of elections
-Running independent and fusion campaigns
Here's a summary of why it failed...
By the late 1890s, under relentless attack – propaganda campaigns warning of a “second Reconstruction” and “Negro rule,” physical intimidation, violence, and targeted assassinations of leaders and foot soldiers – the movement was crushed. A key figure in the attack on Black Populism was White Populist leader Ben Tillman. Black Populism was destroyed, marking the end of organized political resistance to the return of White supremacy in the South in the late nineteenth century. Nevertheless, Black Populism stands as the largest independent political uprising in the South until the modern Civil Rights movement.