|May 22, 1804||The Lewis and Clark Expedition officially begins as the Corps of Discovery departs from St. Charles, Missouri.|
Wait I thought it was May 14th 1804 ? This is what we located regarding the discrepancy in the dates.
There were 33 people, including 29 participants in training at the 1803–1804 Camp Dubois winter staging area in Illinois Territory, near present day Hartford, Illinois. They left on May 14, 1804, and met up with Lewis in Saint Charles, Missouri, a short time later (May 22?); the corps followed the Missouri River westward. Soon they passed La Charrette, the last Euro-American settlement on the Missouri River.