Camp Jackson Affair
1861 CE.
Shown on the map at 38.637°, -90.237°.
The Camp Jackson affair, also known as the Camp Jackson massacre, occurred during the American Civil War on May 10, 1861, when a volunteer Union Army regiment captured a unit of the Missouri Volunteer Militia at Camp Jackson, outside the city of St. Louis, in the divided slave state of Missouri. The newly appointed Union commander in Missouri, Brigadier General Nathaniel Lyon, had learned that the ostensibly-neutral state militia training in Camp Jackson was planning to raid the federal arsenal in St. Louis. That led to him and his regiments, consisting mostly of pro-Union German immigrants, marching into St. Louis and capturing the rebels. After capturing the entire unit, Lyon marched the captives into town to parole them. En route, hostile secessionist crowds gathered and began throwing rocks and shouting ethnic slurs at Lyon's regiments. After a drunk man fired into their ranks, fatally wounding a soldier, Lyon's men opened fire on the mob, killing at least 28 people and injuring dozens of others. Several days of rioting throughout St. Louis followed.
Text from the Wikipedia article Camp Jackson affair, licensed CC BY-SA 4.0.