On August 6, the following notable historical events related to Missouri have been recorded:

• 1804: The Lewis and Clark Expedition was near present-day Council Bluffs, Iowa, across from Missouri’s Atchison County, on or around August 6. They continued documenting the region’s resources and interactions with Otoe and Missouri tribes, advancing their exploration of the Louisiana Purchase.
• 1838: During the Mormon War in Missouri, conflicts escalated. On August 6, the Gallatin Election Day Battle occurred in Daviess County, where non-Mormon residents attacked Mormon settlers attempting to vote, marking a significant escalation in the conflict that led to the Mormon expulsion order later in 1838.
• 1861: During the Civil War, Missouri remained a battleground. On August 6, Union forces under General Nathaniel Lyon were finalizing preparations near Springfield, Missouri, for the Battle of Wilson’s Creek, which took place four days later, a major engagement in the state.
• 1870: The Kansas City Stockyards expanded operations around August 6, solidifying Kansas City’s role 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 6 featuring international agricultural exhibits and early Olympic events, highlighting Missouri’s global cultural and economic prominence.
• 1945: On August 6, the atomic bomb was dropped on Hiroshima, and Missouri played a role in the war effort. The Monsanto Chemical Company in St. Louis was involved in producing components for the Manhattan Project, underscoring Missouri’s contribution to World War II.