On August 15, the following notable historical events related to Missouri have been recorded:
- 1804: The Lewis and Clark Expedition was near present-day Omaha, Nebraska, across from Missouri’s Atchison County, on or around August 15. They continued documenting the region’s geography and interactions with Native American tribes, advancing their exploration of the Louisiana Purchase.
- 1838: During the Mormon War in Missouri, tensions remained high. On or around August 15, non-Mormon vigilantes in Daviess and Carroll Counties continued their campaign against Mormon settlers, with skirmishes escalating the conflict that led to the Mormon expulsion order later in 1838.
- 1861: During the Civil War, the aftermath of the Battle of Wilson’s Creek (August 10) was ongoing in Missouri. On August 15, Union forces were regrouping after their defeat near Springfield, while Confederate forces maintained control in southwest Missouri, underscoring the state’s pivotal role in the conflict.
- 1870: The Kansas City Stockyards expanded operations around August 15, reinforcing Kansas City’s position as a major livestock trading hub and boosting Missouri’s agricultural economy.
- 1904: The St. Louis World’s Fair, or Louisiana Purchase Exposition, was ongoing, with August 15 featuring international cultural exhibits and early Olympic events, highlighting Missouri’s global prominence.
- 1945: On August 15, Japan’s surrender marked the end of World War II, celebrated across Missouri. In St. Louis and Kansas City, public celebrations erupted, and Missouri’s contributions, including the Weldon Spring Ordnance Works’ production of explosives, were recognized as critical to the war effort.