New York (State). Bureau of Records of the War of the Rebellion.

These abstracts were compiled pursuant to Laws of 1887 authorizing the Adjutant General "to procure copies of all military records relating to New York volunteers in the war of the rebellion, not on file in his office from the proper departments of the general government."

In addition the Adjutant General was "to establish as part of his office a bureau of records of the war of the rebellion, in which all records in his office relating to said war, and the records and relics of the bureau of military statistics shall be united and kept."

Although the exact collation date of these records is unknown they were probably produced during the same period when the abstracts for men who served in New York volunteer units, the United States and Marine Corps, or State Militia were being compiled. According to annual reports submitted by the chief of the Bureau of Records of the War of the Rebellion to the Adjutant General, this was between 1887 and 1907.

Under provisions governing the conscription of men into the army by the federal government during the Civil War, men who been drafted were allowed to procure substitutes to serve in their place. The designation "unassigned" refers to men who were located at various recruiting depots and stations when recruiting was ceased by the federal government; men who were permanently assigned duty at these depots and stations; and men who deserted at the depots or stations before being assigned to a unit or en route to their unit.