In the early 1800s, which major North American river were many American settlers using for trade?

Missouri River

Explanation:

The importance of the river for transportation and trade greatly increased in the early 1800s as paddle wheeled steamboats became popular. Cities along the Mississippi such as St. Louis boomed. During the Civil War, both the North and the South used the river for transportation.

answer:

The Tobacco Colonies

Explanation:

The first English settlement in North America had actually been established some 20 years before, in 1587, when a group of colonists (91 men, 17 women and nine children) led by Sir Walter Raleigh settled on the island of Roanoke.