Camp Jackson affair
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.
Lyon's actions ensured Union control of St. Louis and Missouri for the rest of the war but also deepened the ideological divisions within a state that had initially sought to remain neutral in the larger conflict.
Missouri was a slave state, and many of its leaders were Southern sympathizers who favored secession and joining the Confederacy when the Civil War began.
On February 13, Brigadier General Daniel M. Frost enrolled five companies of St. Louis-area Minutemen as the new 2nd Regiment of the Missouri Volunteer Militia.
This sparked fears that Confederates would also seize the much larger St. Louis Arsenal, which had nearly 40,000 rifles and muskets, the largest stockpile in any slave state.
By order of the War Department, Lyon's next action was to move the arms held in the St. Louis Arsenal out of reach of Missouri secessionists.
Missouri Governor Claiborne Fox Jackson had been elected in 1860 on the ticket of the pro-Union Douglas faction of the Democratic Party but privately supported secession.
Since the Constitutional Convention had voted against secession, Jackson and his fellow secessionists decided to carry it out by seizing St. Louis by force and presenting the people of Missouri with a fait accompli.
In mid-April 1861, Jackson wrote to Confederate President Jefferson Davis and asked for heavy artillery to breach the walls of the arsenal.
[3] Around May 1, Jackson called out part of the Missouri Volunteer Militia for "maneuvers" near St. Louis, under the command of Brigadier General Daniel M. Frost.
On May 9, the steamer J. C. Swan delivered the Confederate aid: two 12-pound howitzers, two 32-pound siege guns, 500 muskets, and ammunition in crates marked as Tamoroa marble.
Militia officers met the shipment at the St. Louis riverfront and transported it to Camp Jackson, 6 miles (9.7 km) inland.
Exactly what provoked the shooting remains unclear, but the most common explanation is that a drunkard stumbled into the path of Lyon's marching soldiers and fired a pistol into their ranks, fatally wounding Captain Constantin Blandowski of the 3rd Missouri Volunteer Infantry.
Colonel Henry Boernstein, commander of the 2nd Missouri Volunteer Infantry and publisher of the Anzeiger des Westens, a German-language newspaper in St. Louis, remarked in his memoirs that he gave several of his men leave to visit their families on the morning of May 11 and that "Most of them did not return... until it grew dark, with clothing torn, faces beaten bloody, and all the signs of having suffered mistreatment... Two of them never returned and they were never heard of again.
[citation needed] Martial law was imposed, and with the arrival of federal regulars to relieve the German volunteers, the violence came to an end.
Many Missouri Unionists considered the agreement a capitulation to Jackson and the secessionists and lobbied President Abraham Lincoln for Harney's removal from command.
Against the advice of his senior officers, Jackson exercised his authority as commander-in-chief and ordered the State Guard to make a stand at Boonville.
Nativism, mistrust of the federal government, fears for and of slavery, and states' rights issues all played roles in provoking the Camp Jackson affair.
