this is the answer school will ask you for:
In the 1860s, the Copperheads, also known as Peace Democrats, were a faction of Democrats in the Northern United States of the Union who opposed the American Civil War and wanted an immediate peace settlement with the Confederates.
this is my opinion :
white ppl coudln't do anything without blacks so both sides knew black ppl were strong so they promised them freedom and payments so they could join them.