Until the late 1800s the united states had expanded by settling territory in

Until the late 1800's the United States has expanded by settling territory in westward countries. 

In late 1800 the United States has its westward expansion over the Appalachian mountains into the new states and territories.  They transfer into Texas, California, and other western islands that belongs to Mexico. Americans also arranged to Oregon country. They expand westward to rise and to have changed in American politics.