Located on 0.838 acres of land, the 24,055 square-foot Romanesque Revival style armory was designed by Issac G. Perry, who also finished the design and supervised. the construction of the State Capitol building in Albany. Originally occupied on November 11, 1895. In 1959, a motor vehicle storage garage for ambulances and trucks was added to the building. The outside of the three story building is brick, slate and metal; inside it is timber construction. The corner tower is 65 feet high with a battlemented parapet. When built, the Drill Hall, located on the first floor, had gas lights. The Mezzanine Floor consists of a wooden locker-room, built at the turn of the century. There are also offices throughout the facility. The Drill Hall, where soldiers gather for formations, has also been used for public functions.
The armory's original occupant was the 18th Separate Company, organized on Nov. 6, 1876, later Company K 2nd Regiment (1898), which saw action in the Spanish American War (May 16-Oct. 29, 1898) and the Mexican Border War (June 23-Oct. 8, 1917). Some 162 people who passed through the armory served in World War 1 with the 105th Regiment 27th Division, from Aug. 8, 1917 to April 1, 1919; 110 went to World War II with the 105th Regiment 27th Division (Oct. 15, 1940 to Dec. 31, 1945). Unit designations changed over the years with there being a HHC 1st Bn 186 FA in 1961, and Support Company 2nd Bn 105th Infantry in 1986, until redesignated 646th Medical Company. The two units that operated out of the Warren Street armory at its Centennial were the 646th Medical Company, now Detachment 1 Company C(medical) 427 Foward Support Battalion, and Detachment 1 Co. C 3rd Battalion 108th Infantry, now 2nd Battalion 108th Infantry. Elements of the 646th marched in President John F. Kennedy's inaugural parade and served during the World Cup Games at Lake Placid in 1979, the 1980 Winter Olympics, and the blizzard of 1993.