On September 16, the following notable historical events related to Missouri occurred:

• 1806: The Lewis and Clark Expedition was in the St. Louis area on or around September 16, nearing the end of their exploration of the Louisiana Purchase, preparing to return to St. Louis, which served as their final destination and a key hub.
• 1846: Missouri volunteers for the Mexican-American War, including the First Missouri Mounted Volunteers under Alexander Doniphan, were departing St. Louis around September 16, heading for their campaign in the Southwest.
• 1861: During the Civil War, the First Battle of Lexington was intensifying in Missouri. On or around September 16, Confederate forces under Sterling Price continued their siege of Union troops in Lexington, a significant early conflict in the state.
• 1895: The Missouri Botanical Garden in St. Louis hosted a major public exhibition around September 16, showcasing rare plant species and reinforcing its reputation as a leading botanical research center.
• 1920: The Kansas City Stockyards processed a record number of livestock around September 16, underscoring Kansas City’s role as a major agricultural hub and boosting Missouri’s economy.
• 1998: The St. Louis Cardinals played a notable game against the Pittsburgh Pirates at Busch Stadium on September 16, with Mark McGwire hitting his 67th home run of the season, continuing his record-breaking campaign and cementing Missouri’s baseball legacy.