[3] Osborn and his command saw action in the 1862 Valley Campaign against Confederate forces under Lt. Gen. Thomas Jonathan "Stonewall" Jackson, participating in the Battle of Port Republic on June 9.

[4] Osborn was badly wounded at the Battle of Drewry's Bluff on May 14, 1864, when a musket ball shattered his right elbow and lodged in his arm.

[6] On April 2, 1865, Osborn's command was instrumental in the capture of Fort Gregg during the Union breakthrough, and he brevetted to major general to rank from that date.

[6] Osborn returned to his legal practice in Chicago, engaged in several business ventures, and he also held several federally appointed positions.

[9] In the spring of 1904, Osborn died in Washington, D.C., after suffering for ten hours from a massive cerebral hemorrhage that paralyzed him.