As the United States acquired more land between 1803 and 1850, what issue significantly increased sectional tensions?

I would say Slavery

Explanation:

One example of this is the time after Louisiana Purchase in 1803. Missouri wanted statehood as a slave state. However, the Tallmadge Amendment was proposed where no slaves could be imported, and children born after Missouri's admission are free. Southerners disliked this and the Missouri Compromise was made to admit Missouri as a slave state and Maine as a free state to maintain the northern and southern power in the government.

There are so many times when Congress fought over slavery such as Bleeding Kansas and the Great Compromise of 1850.

women should have the same rights as men

sorry i really dont know