The following is taken from New York in the War of the Rebellion, 3rd ed. Frederick Phisterer. Albany: J. B. Lyon Company, 1912.
This regiment, then located at Albany, now not in existence, was ordered April 9, 1861, to proceed to Washington, D. C. Nine companies left the State April 27, 1861, and the tenth company (Company A), May 1, 1861. Companies A and R were known, respectively, as the Albany Republican Artillery and the Burgesses Corps. The regiment, commanded by Col. Michael K. Bryan, served at and near Washington, where it was mustered in the United States service for three months. It was mustered out at Albany, August 4, 1861.
June 5, 1862, the regiment (six companies), commanded by Colonel Bryan, again left the State, having been mustered in the United States service for three months, atAlbany, May 31, 1862. It served at Suffolk, Va., in the 7th Corps, and was mustered out at Albany, September 8, 1862.
The regiment lost by death in its service in 1861, of disease, three enlisted men; in 1862, drowned, one enlisted man; total, four. And it took part in the advance into Virginia and occupation of Arlington Heights, May 24, 1861.

The following is taken from Third Annual Report of the Bureau of Military Statistics of the State of New York, Albany: [The Bureau], (C. Wendell), 1866.
TWENTY-FIFTH REGIMENT, N. Y. S. MILITIA.
The Twenty-fifth Regiment was organized in the city of Albany and is in the Ninth brigade, Third division of the uniformed Militia of the State. The following were the field officers in 1861:
Colonel — Michael K. Bryan.
Lieutenant-Colonel—James Swift.
Major—David Friedlander.
By Special Orders No. 52, of April 19th, 1861, Major-General Cooper was directed to detail the Twenty-fifth regiment for immediate service at Washington, to report to the President, and to serve until relieved by other regiments ; and on the 22d of April, in pursuance of further orders, the regiment proceeded by special train over the Hudson River railroad to New York. At the time of its departure from Albany, the regiment numbered over 500 men, which number was subsequently considerably increased by the addition of the Burgesses Corps, which joined the Twenty-fifth in Washington immediately after the 1st of May, being designated as company "R" of the regiment.
The scenes, attending the departure of the Twenty-fifth from the State Capital, were exciting. Long before the hour appointed for its march, in the vicinity of its armory, crowds of anxious spec-tators assembled to witness the leaving, and the friends and relatives of the soldiers, to say farewell. When the drums beat for the regiment to move, those collected about the armory moved with it, and the mass received constant additions, so that when the Twenty-fifth had reached the junction of Broadway and State street, the whole population of the city appeared to be in the streets, and from the Exchange, along Broadway to Steuben street, and down Maiden lane to the ferry, the crowd was so great that it was almost impossible to discern the moving column as it pursued its course-to the boat. Public and private buildings were decorated with banners; and from innumerable windows and balconies, waved small flags, or handkerchiefs, in token of warm approbation; and thousands of throats sent up such huzzas as had hot been heard in the old Dutch town within the memory of the "most ancient inhabitant." The Mayor of the city, standing in front of Stanwix Hall, made a brief and appropriate address to the regiment as it halted on its march to the ferry, and bade their adieu, on the part of life, follow citizens, with wishes for a speedy and glorious return ; and then, amid the booming of cannon and strains of martial music, the Twenty-fifth departed for Washington. Upon reaching the city of New York, the regiment embarked upon the steamer Parkersburgh and sailed for Annapolis, where they landed on the morning of the 26th of April; and the Colonel reported to General Butler, then in command of that post. On the morning of the 29th the regiment arrived in Washington, being the fifth regiment that reached the capital, at that critical period for its defense. Upon its arrival in Washington, it was quartered in a large building near the capitol, and there drilled by Colonel Bryan, and officers of the United States Army several times each day, until they became one of the best drilled Militia regiments in Washington. Immediately on its arrival the commanding officer reported directly to Lieutenant-General Scott, and was by him directed to report with his command to Brigadier-General Mansfield, and the regiment remained under his orders 'till the 23d of May, when it was directed to cross the Long Bridge into Virginia. This direction was complied with on the same night, the Twenty-fifth being the second regiment that reached the Virginia side. The regiment marched directly to Arlington Heights, where it encamped on the morning of the 24th, and soon after commenced the erection of Fort Albany. The fort was built almost entirely by the men of the Twenty-fifth. They also cleared off some 20 acres of woodland in the vicinity of the fort.
The regiment, on its reaching Arlington, captured two of the rebel pickets, with their horses and equipments, who wore among the first prisoners taken in Virginia after the commencement of the war. The fort built by the Twenty-fifth was named Fort Albany in accordance with the decision of the regiment to whom its naming was left by the military authorities at Washington, in compliance with the suggestion of Col. Bryan. At the time of the battle of Bull Run the regiment was occupying Fort Albany; and immediately upon the news of the disastrous result of the battle reaching Washington, Col. Bryan was placed in command of that fort, as well as of several batteries and regiments, stationed in the vicinity, with directions to make a determined stand in case of an advance on the part of the rebel army. Such an advance, however, did not occur, the knowledge of the existence of such works as Fort Albany about Washington contributing, undoubtedly, in a great measure, to deter the rebel leaders from undertaking a movement upon the Capital. Although the Twenty-fifth left the State on the 23d of April, it was not mustered into the service till the 4th of May. It remained in the fort of its erection during the remainder of its term, when it returned to Albany, where it was mustered out of service on the 4th of August. Three of the members of the regiment died in Washington from disease contracted in the service. At the time of the mustering out of the regiment it numbered, including officers and men, 575. Col. Bryan took the Twenty-fifth to the field again in 1862, and subsequently raised the One Hundred and Seventy-fifth regiment of Volunteers, and was killed at Port Hudson. He was a brave and gallant officer.