What effect did the issue of slavery have on political parties in the 1850s

Slavery was THE great debate of the 1850's as was the question of continuing a union that threatened the lives and property of the South. It caused Lincoln's election in 1860 and fueled the movement to secession and war. Slavery was the dividing point over which there was a limit to the compromises that could be effected. It clearly drove the decade as it had shaped the whole century.