Melcher was completing his studies at Bates, and holding a small teaching job in Harpswell. He became engrossed with the patriotism involved with the war and upon concluding his studies he quit his teaching job, and enlisted formally on August 19, 1862 as a private in Company B, 20th Regiment Maine Volunteer Infantry. His brother became interested in following his footsteps but Holman advised him to avoid enlisting and pursue education at Bowdoin College, promising to write each other weekly. A week after enlisting, he was mustered into the United States service at the rank of Corporal. American Civil War After completing his studies at the seminary, he enlisted as a Corporal in the Union Army. Melcher was assigned to the 20th Maine Infantry Regiment which was organized in and equipped at Camp Mason near Portland, Maine, on August 29, 1862 and with it was immediately assigned to the V Corps; serving in that organization for the duration of the war. The 20th Maine first engaged in combat in the Battle of Shepherdstown Ford; the end of the Maryland Campaign. During the Battle of Fredericksburg, Melcher was promoted to Sergeant-Major for "meritorious conduct", by Col. Adelbert Ames. On April 20, 1863 he was promoted to First Lieutenant of Company F. On April 2, 1863, Colonel Joshua Chamberlain, appointed him acting Adjutant of the regiment. He served in this position until army restructuring by the incoming General Ulysses S. Grant, in March. Battle of Gettysburg On July 2, 1863, Melcher took part in the bayonet charge at Little Round Top that helped repulse the Confederate attack. On the second day of Battle of Gettysburg, military forces moved to Little Round Top, where Chamberlain began preparing strategic options, as Maj. Gen. Joseph Hooker was recently replaced by George G. Meade. As fighting raged in the Wheatfield and Devil's Den, brigade commander Col. Strong Vincent had a precarious hold on Little Round Top, an important hill at the extreme left of the Union line. His brigade of four relatively small regiments was able to resist repeated assaults by Brig. Gen. Evander M. Law's brigade of Hood's division. The defense of Little Round Top with a bayonet charge by the 20th Maine was one of the most fabled episodes in the Civil War. Charging Little Round Top dispute There has been some controversy tied to the charge on Little Round Top with historians challenging