That is an interesting question. There has been some historical debate about that. I actually do not think the Baptists came from the Anabaptists.
The Anabaptists were a movement beginning in the sixteenth century and are best known today in terms of groups like the Mennonites and the Amish. They reacted viscerally against the wealth of the Roman Catholic Church in the sixteenth century but saw the antidote as a simple, disciplined life. The Anabaptists were often not very strong on theology or understanding justification by faith alone.
I think the real history of the Baptists rose out of seventeenth century Calvinist circles in England who felt that practicing believer’s baptism was a better way to spiritual discipline and a properly organized church.