In January of 1803, Jefferson requested $2500 from Congress to pay for the costs of the trip. Thomas Jefferson then commissioned Capt. Meriwether Lewis (his presidential aide) to explore the newly purchased Louisiana Territory. This territory is what is now the northwest United States. Before Lewis met up with Clark, he began the expedition on August 30, 1803 in Pittsburgh PA. Lt. William Clark would offer to join Lewis on the expedition weeks later on October 13, 1803 at Camp Dubois (in present-day Indiana). They then named their team the "Corps of Volunteers for North Western Discovery." At the time, Lewis was 29 years old and Clark was 33. From there, they sailed down the Ohio River towards St. Louis.