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, located in 1863, in Dutchess county, is now not in existence except its Company A.

This Company A was organized immediately after the bombardment of Fort Sumter, S. C, as the Poughkeepsie Drill Guards; May 14, 1861, this name was changed to "Ellsworth Grays"; October 27, 1862, the company joined the National Guard and became Company A of this regiment. When the regiment was disbanded, December 17, 1881, this company was retained, but its designation was changed to 15th Separate Company. This company was on duty at Buffalo in August 1892, during the switchmen's strike. In the Spanish-American war it served as Company K, 1st N. Y. Volunteer Infantry, from May 29, 1898, to February 26, 1899.

Company D of this regiment was organized November 28, 1828, as a company of infantry and known as the Poughkeepsie Guards; in 1832 the company was assigned to the 84th Militia as Company F; in 1848 it was transferred to the 21st Militia as its Company D, and when that regiment was disbanded this Company D became the 19th Separate Company. This company was frequently called into active service between 1847 and 1852, while the Hudson River railroad was being built, to quell labor riots. July 17, 1869, it was on duty quelling a riot at Pleasant Valley; in July, 1877, it was under arms during the railroad riots, and in August, 1892, it was on duty at Buffalo during the switchmens' strike. It was disbanded June 21, 1897. In September, 1862, about forty members of this Company D entered the United States service, forming Company B, 150th Volunteers, and June 18, 1863, this regiment was ordered to proceed to Harrisburg, Pa. It left the State, six companies, commanded by Col. Joseph Wright, June 26, 1863; was mustered in the United States service for thirty days from June 27, 1863, to Baltimore, Md., served in the 2d Separate Brigade, Middle Department, 8th Corps, and it was mustered out at Poughkeepsie, August 6, 1863.