Who wanted new states to be added into the nation as slave states?

The Confederates / pro-slavery

Explanation:

At that time, there were two different groups that exist In United States. The pro-slavery group (which mainly consist of the southern states), and the Abolitionist group (which mainly consist of the northern states).

Both of these group involved in a long-tedious conflict regarding whether United States should continue the practice of slavery. In the end, they settle by dividing United States into 'slave states' which allow slavery, and 'free state' which banned slavery.

After the Louisiana Purchase, United States acquire more states to be added as a part of the country. The pro-slavery wanted these new states to be slave states because it will provide their group with more economic power against the abolitionist group.

these conditions long with a short growing season made farming difficult.

explanation:

the north has a climate of warm summers and snowy cold winters. the terrain is rocky, hilly, and not good for farming.

an era of negotiation.

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