Osgood T. Hadley was born in Nashua, New Hampshire, and was a resident of the state when he answered the call to serve during the American Civil War. He mustered into the 6th New Hampshire Veteran Infantry, a unit known for its heavy involvement in the grueling campaigns of the Eastern Theater. Within the ranks of Company E, Hadley eventually rose to the rank of Corporal and was entrusted with the role of color bearer—one of the most dangerous and prestigious positions on the battlefield.

On September 30, 1864, during the Battle of Poplar Springs Church (near Pegram House, Virginia), Corporal Hadley’s unit was heavily engaged in an attempt to extend the Union lines around Petersburg. Amidst the chaos of the Confederate counterattack, the colors of the 6th New Hampshire were at risk of being captured.

Displaying remarkable personal gallantry, Hadley defended the flag against the enemy. Despite the intense pressure of the action, he managed to keep the colors flying and successfully brought them safely back to Union lines. For his bravery and his refusal to let the regiment’s standard fall into enemy hands, he was later awarded the Medal of Honor.