Answer:
Before the American Civil War, anti-slavery Republican Party leaders like Abraham Lincoln wanted to stop slavery from spreading to new states and territories in the American West, not abolish it. They also proposed this so that a civil war would not occur between the colonies, but as we all know, they split into the Confederacy and the Union, and started the American Civil War, which was over slavery.
Main Answer:
The U.S. government wanted to stop slavery from spreading to new states and territories in the American West, not abolish it.