This is the period of American History starting from the creation of the United States Constitution. In this time, the United States has plenty of growing pains operating as a new country. And it was growing fast, most dramatically with the Louisiana Purchase brokered between U.S. President Thomas Jefferson and French Emperor Napoleon Bonaparte, which literally doubled the land width of the US overnight. Of course, this land had to be explored, and that's where the famous expedition led by Lewis and Clark came in. Examples of Antebellum America include: