3. During the early 1800s, US territory .

a) expanded
b) shrank
c) was divided

The answer is A. It expanded.

Explanation:

The United States was expanded and explored in many ways during the first and subsequent decades of the 1800s. We bought territory from the French in the Louisiana Purchase, make roads for pioneers to reach the Mississippi River, then sent explorers with Indian guides to breech the passes of the Rocky Mountains and find a route to the Pacific Ocean.

the option which was not a function of missionaries in the northwest was the first one - they established posts for trading furs and other goods.

missionaries were sent around the world to spread religion and their knowledge and others - they were not merchants who sold furs and other goods.