It didnt, its all fake news
They allowed for travel against a rivers current Hope this helps! ;D
Answer:
The philosophy drove 19th-century U.S. territorial expansion and was used to justify the forced removal of Native Americans and other groups from their homes. The rapid expansion of the United States intensified the issue of slavery as new states were added to the Union, leading to the outbreak of the Civil War.
American leaders were feared that the United States would shut out of the valuable china trade.
