- The border state of Missouri has assets that both sides want to appropriate for themselves. While his commanding officer at the St. Louis Federal Arsenal, US General William S. Harney is out of town, US Captain Nathaniel Lyon with 6,000 combined militia and regulars including Francis Blair Jr.’s disliked German-immigrant Home Guard, marches 4 ½ miles from the arsenal to attack the 669 Missouri Volunteer Militia under command of General Daniel M. Frost at Camp Jackson. In the fight, Lyon seizes the Camp Jackson barracks.
When the local citizenry sees this display, their anger boils over in mass riots, with civilians hurling rocks, paving stones, and insults at Lyon’s men, especially the Germans. Then a drunkard stumbles into the path of the marching soldiers, and fires a pistol into their ranks, fatally wounding Captain Constantin Blandowski. Capt. Lyon’s men, especially the German Home Guard respond by firing first over the heads of the crowd, then into them, killing some 28 people, some of whom were women and children, and wounding over 100 more.
Two uninvolved non-combatants who just happened to be in town that day were nearly killed in the shooting: William T. Sherman, walking with his son and brother-in-law, and Colonel Ulysses S. Grant of the 21st Illinois Volunteer Infantry. Thus, Federals secure control of St. Louis, Missouri, with the rifle and bayonet./1861
- President Jefferson Davis in Montgomery, Alabama, orders the purchase of warships and munitions for the Confederate government. Secretary of the Navy Stephen F. Mallory suggests the addition of ironclads to the small Confederate Navy, for advantage over the U.S. Navy’s much larger and more diverse fleet./1861
- President Lincoln directs the commander of U.S. forces on the Florida coast to suspend the writ of habeas corpus, "if he shall find it necessary."/1861
- In Wheeling, western Virginia, the first company of US Virginia Infantry is mustered into Federal service./1861