87th New York Volunteer Infantry Regiment-- Part 1

From Wikipedia.

I am still trying to find out some more about the death of Thomas Bailey Aumack.  What I have found is very confusing.  Was he wounded at the Battle of Antietam or wounded somewhere else?  Did he contract dysentery and was honorably discharged from service to die at home?

I'll first take a look at the 87th New York.  

I went through the list of Union regiments at Antietam and did not find the 87th New York among them.

The 87th  New York Volunteer Infantry was also referred to as the 13th Brooklyn or the  13th New York State Militia.

It was organized at Brooklyn, New York, on November 14, 1861, and mustered in for three years service on November 20 under the command of  Colonel Stephen A. Dodge.

The regiment became part of the Army of the Potomac and ceased to exist on September 6, 1862, when it was consolidated with the 40th New York Infantry.  Company B was transferred to  the 173rd New York Infantry on September 11, 1862.

--Old Secesh