(1827 - 1878)
Home State: New York
Command Billet: Commanding Regiment
Branch of Service: Infantry
Unit: 4th New York Infantry
Before Antietam
He served in the Mexican War (1847-8) and was a lawyer in New York. Age 35, he enrolled in New York City on 24 April 1861 as a Captain and mustered as Lieutenant Colonel of the 4th New York Infantry on 15 May 1861.
He and his commander, Colonel Alfred W Taylor violently and public disagreed and verbally abused each other. By June 1862 both had been court martialed. Colonel Taylor, charged in April with drunkenness, among other things, was convicted at his trial but the verdict was eventually set aside; he resigned from the service in July 1862.
Lieutenant Colonel MacGregor was charged in June 1862 with 'conduct unbecoming' and 'prejudicial to good order', but was acquitted.
On the Campaign
He was in command of the regiment in Maryland.
The rest of the War
He was promoted to Colonel on 10 October 1862 (to date from 9 July) and was wounded at Fredericksburg, VA in December 1862 and again at Chancellorsville, VA in May 1863, before mustering out with the regiment later that month. He was brevetted Brigadier General in March 1865 for his wartime service.
After the War
He was a lawyer in New York City by 1869.
References & notes
His service from the Adjutant General1 with details from Eicher & Eicher,2 both as McGregor. The story of his turbulent relationship with Colonel Taylor and their 1862 Courts Martial is found in Thomas P Lowry's Tarnished Eagles (1997), source also of his picture, from a photograph at the US Army Military History Institute (now Heritage and Education Center). Personal details from family genealogists. His gravesite is on Findagrave.
He married Mary Catharina Van Buren (1827-) and they had two sons (born 1854, 1856). He married again, Amelia C. Garrison in September 1869 in Manhattan.
Birth
1827; Upper Red Hook, NY
Death
04/23/1878; New York City, NY; burial in Cypress Hills National Cemetery, Brooklyn, NY
1 State of New York, Adjutant-General, Annual Report of the Adjutant General of the State of New York [year]: Registers of the [units], 43 Volumes, Albany: James B. Lyon, State Printer, 1893-1905, For the Year 1898, Ser. No. 17, pg. 718 [AotW citation 29415]
2 Eicher, John H., and David J. Eicher, Civil War High Commands, Stanford: Stanford University Press, 2001, pg. 359 [AotW citation 29416]