Definitely: social organization of clans and tribes and moved around a lot. Might be livestock was only surplus if you mean that livestock was kept from season to season.
A pastoral society is a nomadic association of people who move with a herd of trained animals, which they rely on for food. The word pastoral comes from the Latin root word pastor, which determines shepherd. Someone living in a pastoral society is named a pastoralist. Everyday life is focused upon the tending of herds or droves.
Lincoln said this because his ultimate goal was to preserve the Union. Although he detested slavery on moral and economic grounds, he thought that it would eventually die out on its own, if it could be contained where it was.