From the first engagement of the regiment to the end of its three years' memorable service, Captain Daggett proved a faithful and gallant soldier. He was promoted major, January 8th, 1863; on January 18th, 1865, was commissioned lieutenant-colonel of the 5th Regiment, United States Veteran Volunteers, Hancock Corps, and was brevetted colonel and brigadier-general of volunteers, March 13, 1865, for "gallant and meritorious services during the war." He also received the brevets of major in the United States Army for "gallant and meritorious services at the battle of Rappahannock Station, Va.," November 7, 1863, and lieutenant-colonel for "gallant and meritorious services in the battle of the Wilderness, Va." Immediately after the battle of Rappahannock Station, the captured trophies, flags, cannons, etc., were escorted, by those who had been most conspicuous in the action, to General Meade's headquarters, Colonel Daggett being in command of the battalion of his brigade. General Upton to whom he owed this distinction, wrote of him as follows:
"In the assault at Rappahannock Station, Colonel Daggett's regiment captured over five hundred prisoners. In the assault at Spottsylvania Court House, May 10, his regiment lost six out of seven captains, the seventh being killed on the 12th of May, at the "angle," or the point where the tree was shot down by musketry, on which ground the regiment fought from 9.30 A.M. to 5.30 P.M., when it was relieved. On all these occasions Colonel Daggett was under my immediate command, and fought with distinguished bravery.
"Throughout his military career in the Army of the Potomac, he maintained the character of a good soldier and an upright man, and his promotion would be commended by all those who desire to see courage rewarded."
General Upton also wrote to the Governor of Maine as follows:
"I would respectfully recommend to Your Excellency, Major A.S. Daggett, formerly 5th Maine Volunteers, as an officer highly qualified to command a regiment. Major Daggett served his full term in this brigade with honor both to himself and State, and won for himself the reputation of being a brave, reliable and efficient officer. His promotion to a colonelcy would be a great benefit to the service, while the honor of his State could scarcely be entrusted to safer hands."
He was subsequently recommended for promotion by Generals Meade, Hancock, Wright and D.A. Russell. He was in every battle and campaign in which the Sixth Corps, Army of the Potomac, was engaged, from the first Bull Run to Petersburg, and was twice slightly wounded. On July 28, 1866, without his knowledge or solicitation, he was appointed a captain in the U.S. Regular Army, on recommendation of General Grant, and has since been promoted colonel in this service. During his subsequent career he has won the reputation of being a fine tactician and of being thoroughly versed in military law, as is indicated by Major Hancock's commendatory words in 1878:
"I look upon him as by far the best tactician in the regiment, and as for a thorough, clear knowledge of tactics his superior is not in the army. As regards military and civil law, I know of no one so well informed."
His ability and soldierly qualities have also been highly commended by General Crook, Colonel Hughes—Inspector-General in 1891—and Colonel ----, Inspector-General in 1892.
Not only as a soldier, but in many other ways, has General Daggett distinguished himself. As a public speaker the following was said of him by the Rev. S.S. Cummings, of Boston:
"It was my privilege and pleasure to listen to an address delivered by General A.S. Daggett on Memorial Day of 1891. I had anticipated something able and instructive, but it far exceeded my fondest expectations. The address was dignified, yet affable, delivered in choice language without manuscript, instructive and impressive, and highly appreciated by an intelligent audience."