Answer:
Slavery
Explanation:The United States became a continental nation with the purchase of Louisiana from France in 1803 and the settlement of the lands beyond the Appalachian Mountains. Westward expansion fueled conflict with Native populations and led to their forced removal. By 1820, 2 million Americans lived west of the Appalachians, out of a total national population of 10 million. The regional cultures that had developed along the Atlantic Coast—New England, Middle Atlantic, Chesapeake, and Carolinas—were transplanted into the Old Northwest (Ohio, Indiana, Illinois, Michigan, and Wisconsin) and the Old Southwest (Arkansas, Kentucky, Louisiana, Missouri, Tennessee, and Texas). But although Americans had begun to identify themselves as a nation, they were divided by sectional interests that deepened with rapid industrialization and the question of slavery.
i think its 3 lol give me brainliest now
B the I think the answer is b
They started domesticating wheat. This wasn't their main feat however since they also started herding sheep and domesticating goats. These two enabled them to stop moving around like nomads and make a real civilization in the area which resulted in what is now known as history.
The answer to this question is that it is made up of salt water marshes.