The child or childer by a slave woman is/are considered slave by birth. It was part of the <span>Virginia Slave Act of 1662 that states that all child of a slave women are considered slave for a lifetime. While the child of the free woman is always considered to be free. </span>
It's a because during the middle ages kingdoms conquer other nations by the numbers as soon as the child has education he (I say he because they didn't allow women to have education back then) he will enlist into one of the European nations and fight.
They were both farmers and the north used more factories while the south didn't.