This database contains service record cards for veterans of the New York Guard for both the WWI and WWII eras. Most of the cards document the service records for soldiers mustered into state service when the New York Guard was reorganized to replace New York National Guard units that were being activated into federal service just prior to and during the Second World War. Information varies but minimally includes name, address, date of enlistment, company, and regiment.
The New York State Archives website provides the following background on the New York Guard:
On August 3, 1917, the Adjutant General, in order to comply with the provisions of the State Constitution requiring that troops be available to the Governor for the protection of life and property of the citizens of New York, organized a State Military Force known as the New York Guard. The force replaced the New York National Guard, mobilized into federal service on August 5, 1917. One of the principal duties of the guard was to actively guard public property, principally, the water supply of the City of New York from the northern boundary of the city including the entire Croton Aqueduct system. When the federalized New York National Guard units were returned to State status after the Armistice in 1918, the New York Guard units were deactivated.
In October 1940, the New York Guard was reorganized and mustered into state service to replace New York National Guard units which were being activated into federal service. By 1944, the New York Guard had attained an aggregate strength of approximately 25,000 officers and enlisted men. Again in 1951, after several New York National Guard units were ordered into federal service, the New York Guard was reorganized and served a limited mission preparing plans to furnish logistical support in the event of a national emergency. Pursuant to federal legislation for the creation of State Defense Forces, enacted by the 84th Congress in 1955 and State legislation enacted in 1958, the New York Guard was reorganized as a reserve land force of the Militia of New York.
You can read more about these records on the New York State Archives website.