Eri D. Woodbury was born in the quiet town of Francestown, New Hampshire. While his roots were in the Granite State, he was residing in St. Johnsbury, Vermont, when the Civil War called for volunteers. He enlisted in the Union Army, joining the ranks of Company E, 1st Vermont Cavalry.

By the autumn of 1864, Woodbury had risen to the rank of Sergeant. On October 19, 1864, during the Battle of Cedar Creek in Virginia, the 1st Vermont Cavalry was ordered to charge against a retreating Confederate force. Amidst the chaos of the pursuit, Woodbury found himself separated from his main unit and face-to-face with four Confederate infantrymen.

Though outnumbered, Woodbury did not hesitate. He drew his saber and charged the group alone, demanding their immediate surrender. His sheer determination broke the resolve of the retreating soldiers. The four men laid down their arms, surrendering their rifles and the regimental flag of the 12th North Carolina (C.S.A.) to the lone Sergeant. For these actions, Woodbury was later awarded the Medal of Honor.