In colonial America, Africans "contributed" to society by being a source of income for people who bought and sold them into slavery. They also contributed by being laborers in the southern plantations.
Women contributed to the society by being a house wives --meaning they took care of the house-- as well as cooking meals for the family and taking care of the children.
Native Americans, in the earlier days, contributed by trading with settlers and teaching them how to do things in their environment.
(Sorry I really don't know what the children did)
Judging from your other questions, I would guess the Aztecs, because they had an extremely advanced civilization relative to their time period. However, you might want a second opinion to verify this. Hope this helps.
The main reason was the South wanted to preserve slavery. The North wanted to abolish it. If you want some other reasons than slavery, let me know, and I will do my best to add more to this answer.
<span>The only state added after 1800 that is east of the Appalachians was Florida. It was added in 1845, due to the numerous Indian problems, poor soil and the fact it wasn't a territory until 1822.</span>
The answer is: m<span>essiah</span>
