The average slave owner was a capitalist continually on the move and seeking to improve himself. Slaves were a commodity to be used, as were the democratic politics of slaveholders and the southward and westward expansion of the United States. The differences between North and South were less obvious than the similarities. The master-slave relationship made the South different. Southerners enslaved blacks, while white Northern Americans embraced anti-black racism. There was constant tension characterized by slavery between slaves and masters. Slaves created the masters' world and constantly threatened to undo it