What does "Everything in the experience of the first white settlers acted as a pressure for the enslavement of blacks" mean?

it probably has something to do with fact the early settlers in south planted tobacco and cotton fields which became base of their economy. This gave rise to the need for cheap labor ... slave traders supplied that need

The whites were forced to enslave blacks because they couldnt inhabit the same land and they needed more workers and didnt want to pay them with money they didnt have