Colonel Charles Tilden was commander of the 16th Volunteer Infantry, part of the 2nd Division of the I Corps in the Army of the Potomac at the Battle of Gettysburg. After fighting for 3 hours on Oak Hill, Tilden's regiment of 275 men was asked to stay back and buy time for the rest of the division to retreat to Cemetery Hill. They held off the Confederates for 20 minutes, buying time for the division to escape. Tilden was captured and was among the 81% casualites of the regiment. Of 275 men present, only 38 would make it back to Cemetery Hill to join the rest of the Division. 

If not for Tilden and the 16th Maine's heroics, the Union may not have secured Cemetery Hill on July 1st, 1863. This would have changed the Battle of Gettysburg and American history from that point. 

Tilden would escape the next year from Libby Prison in Richmond, Va. He would fight against the Battle of Petersburg. He was captured again and also escaped.