* The Louisiana Purchase doubled the size of the United States.
* Zebulon Pike explored the Louisiana Territory and claimed Pike's Peak.
* Lewis and Clark explored the Pacific Northwest and claimed Oregon Country.
Diplomacy
* Thomas Jefferson negotiated the end of the Quasi-War with France.
* John Adams negotiated the end of the American Revolutionary War with Britain.
* John Quincy Adams negotiated the Adams-Onís Treaty with Spain, which established the border between the United States and Spanish Florida.
Economy
* The Industrial Revolution began in the United States.
* Eli Whitney invented the cotton gin, which revolutionized the cotton industry.
* The Erie Canal opened, connecting the Great Lakes to the Atlantic Ocean and making trade much easier.
Politics
* The federal government was strengthened under the presidency of George Washington.
* The Bill of Rights was adopted, protecting individual liberties.
* The Alien and Sedition Acts were passed, limiting free speech and the rights of immigrants.
* The United States fought the War of 1812 against Britain.