Final answer:
The Burr expedition was an attempt by Aaron Burr to establish an independent country in the western United States. Burr was accused of treason and put on trial, but was eventually acquitted due to lack of evidence.
Step-by-step explanation:
The Burr expedition, also known as the Burr conspiracy, took place in 1807 and involved Aaron Burr's attempt to establish an independent country in the western United States. However, the expedition was accused of treason and Burr was put on trial in Richmond, Virginia with Chief Justice John Marshall presiding. Burr was eventually acquitted due to lack of evidence.