Jason Lee had visited Peoria on a national speaking tour about the Oregon country and moving westward.
He recruited sixteen men at the start, but would pick up three more volunteers on the trail - bringing their largest number to nineteen.
The men began to argue and bicker over leadership, which culminated in a near fatal accident a month later causing the eventual dissolution of the Peoria Party.
On July 5, 1839, the remaining members of the Peoria Party reached Bent's Fort, a trading post on the South Fork of the Platte River.
Nine of the original nineteen eventually made it to Oregon - the rest of the group either returned to Peoria or headed in other directions.