Hi John, This is all I have on Michael:' Served Distinguished service, Union, Connecticut, Unit # 90-90. 04/17/1861 to 08/21/1865
Name: Michael McMahon ,
Residence: New Britain, Connecticut
Enlistment Date: 17 July 1862
Distinguished Service: DISTINGUISHED SERVICE
Side Served: Union
State Served: Connecticut
Unit Numbers: 84 84
Service Record: Enlisted as a Private on 17 July 1862
Enlisted in Company F, 14th Infantry Regiment Connecticut on 23 August 1862.
Promoted to Full Corporal on 09 February 1863
Wounded on 03 May 1863 at Chancellorsville, VA
Promoted to Full Private on 25 October 1863 ((Sick), Reduced to ranks)
POW on 08 May 1864 at Ellis Ford, VA (Paroled)
Paroled on 02 March 1865
Mustered out Company F, 14th Infantry Regiment Connecticut on 31 May 1865

One of my 3rd cousins has studied the McMahon brothers service in the Civil War. He has information on John, Patrick and Matthew. Here is his email address:  ehallora@email.unc.edu  You can tell him that I suggested you contact him.  He is very well versed in this McMahon line and their service. I have tons of information on Patrick, but not his brothers. Ann