Volume 3: May 1861

Volume 3 covers May 1861, when Missouri's political crisis deepened despite the State Convention's recent vote to remain in the Union. Public debate continued over whether the state should secede, adopt armed neutrality, or remain firmly loyal to the Union. Unionist newspapers argued that "armed neutrality" was merely a step toward rebellion and warned that Governor Claiborne F. Jackson's policies were designed to move Missouri gradually toward secession. Meanwhile, tensions escalated throughout the state as Union supporters reported harassment by secessionists, militia recruitment increased on both sides, and federal and state authorities maneuvered for control of strategic positions such as the St. Louis Arsenal. Union leaders including Frank P. Blair Jr., Franz Sigel, and others organized Home Guard units, while pro-Southern forces gathered at Camp Jackson near St. Louis.

The crisis reached a turning point on May 10 when Captain Nathaniel Lyon surrounded Camp Jackson and forced the surrender of the Missouri Volunteer Militia under General Daniel Frost. As captured militiamen were marched through the city, violence erupted between civilians and Union troops, resulting in multiple deaths and intensifying political divisions. In the aftermath, the Missouri legislature passed the Military Bill, creating the Missouri State Guard under Sterling Price, while clashes, riots, and reports of persecution against Unionists spread across the state. Negotiations between General William S. Harney and Price briefly attempted to calm the situation, but distrust and continued military preparations ensured that Missouri's internal conflict would soon expand into open warfare.