Slavery was common for various reasons. One of them being climate when the british brought them to america they figured they were used to the heat and moisture. Another was the plantations required alot of attention. They didn't see the africans as equal so they let them sleep around the plantations in barley inhabital places. Another obvious reason is the fact that the southern colonies were on the coast of the Atlantic as was africa so it was a much easier to put the slaves there.