The doctrine of popular sovereignty was used. That meant that people in those states could choose to vote to support slavery and since they were majority then slavery would be permitted. There were even states that were at first non-slave states but then things changed and they voted to introduce slavery into the state and people voted for this and supported this.
Well the first English settlement was really Roanoke, however it was not successful. The first successful one would be the new Virginia colony, later known as Jamestown;)
