1. 12th Amendment

The way a presidential election was conducted changed with the 12th Amendment. It created a separate ballot for President and Vice President.

2. Louisiana Purchase

This was the purchase of the Louisiana Territory which doubled the size of the U.S. The deal was processed as a treaty so that it would be constitutional for Thomas Jefferson to acquire it.

3. Lewis & Clark Expedition

This was the first American expedition of its kind, and spanned from St.Louis to the Pacific Coast.

Major Events