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 Brooklyn, now not in existence, left the State (ten companies) April 30, 1861, under orders to proceed to Washington, D. C. It was there mustered in the service of the United States for three months, and, commanded by Col. Michael Bennett, served at that city and vicinity until it was mustered out at Brooklyn, August 5, 1861.
June 16, 1863, it was again mustered in the United States service, but for thirty days, and, commanded by Colonel Bennett (ten -companies), proceeded to Harrisburg, Pa. It served at that city, Marysville, Carlisle and Gettysburg, Pa., in the 2d Brigade, 1st Division, Department Susquehanna, and was mustered out at Brooklyn, July 22, 1863.
In August, 1864, the regiment (seven companies), then commanded by Col. David A. Bokee, proceeded to Elmira, where it served, and was mustered in the United States service, for 100 days, from various dates in August, 1864. It was mustered out at New York city, November 13, 1864.
In its service in 1864, the regiment lost, died of disease, one enlisted man; it took part in the advance into Virginia and occupation of Arlington Heights, May 24, 1861; in a skirmish near Chain Bridge, Va., June 2, 1861, and near Fort Washington, Pa., July 2, 1863.

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-EIGH'TH REGIMENT, N. Y. S. MILITIA.
The Twenty-eighth Regiment was organised in the city of Brooklyn, and is in the Fifth brigade, Second division of the State Militia organization.
It left the State on the 30th of April, 1861. The official report placed the number of men in the regiment at 563, but the local accounts, published at the time of its departure, put the figures much higher. 
The following were the field officers:
Colonel----Michael Bennett. 
Lieutenant-Colonel—Edward Burns.
Acting Lieutenant-Colonel—W. R. Brewster.
Colonel Bennett was prevented from going out with the regiment by severe injuries received by being thrown from a wagon, out was to join it immediately on his recovery; and, in the mean time, Lieut.-Col. Burns took the command of the regiment. The following extract, gives an account of the departure of the regiment.
" The Twenty-eighth Regiment, N. Y. S. M., composed of the best class of Germans, and commanded by Colonel Bennett, left Brooklyn, N. Y., for the seat of war April 30th. At 11 o'clock the last farewell was said; the regiment formed, about eight hundred men, and headed by Meyer's band and a corps of drummers and fifers, marched through Myrtle avenue and Fulton street to Fulton ferry, where they embarked on board the ferry boat Nassau, and were taken direct to the steamer Star of the South, then lying in the North river. The streets through which they marched were lined with enthusiastic citizens, to bid the troops "Godspeed," and from nearly every house waved the Stars and Stripes, and other inspiring signals. The troops were everywhere cordially received. At the foot of Fulton street a few brief farewells were said, and amid the tiring of cannon and the cheers of the populace, the troops took their departure."
The Twenty-eighth served its term at and near Washington. It was encamped below Arlington Heights. Among the exciting incidents which occurred during its service, the following is mentioned, of June 1st:
At night, word came into the camp of the Twenty-eighth New York regiment that the two dragoons missing from company B, which made the sally on Fairfax Court-House this morning, were captured by the rebels, and were to be hung. Company B was immediately summoned from their quarters, and mounting, rode up to the Court-House, and having, by some means, ascertained the precise location of their comrades, made a dash through the village and recovered the two men, whom they brought back in triumph to the camp.