While searching the OR's for help on captured Union flags. I checked OR 2, "Skirmish at New Creek, West Virginia", June 19th, 1861.
Col A.P.Hill was the brigade commander and sent 2 companies of his own 13th Virginia and Col J.C.Vaughn sent 2 companies of his 3rd Tennessee.
Col A.P.Hill's report:
"Some 250 of the Federal troops, after a slight stand, retired in disorder, with a loss of a few men. The bridge was then burned and Colonel Vaughn retired, bringing with him the two pieces of artillery and a stand of colors."
Col Vaughn's report:
"The enemy's flag, which I forgot to mention, was captured, and other articles of little value."
Now, it did not say what Union regiment, battalion lost a flag. So I did a google search and got lucky.
"Additionally, Dayton was the son of Rev Roland Dayton, a farmer and minister located in the area of 21st Bridge, where the B&O crosses from Maryland into West Virginia just south of New Creek. Whether there was a significant community at 21st Bridge, or if Dayton Sr just lived on his farm there with other locals, is not known, but Dayton Sr. and his large family lived near the railroad bridge that was a much desired target- so much so that it was occupied with the 50th Maryland Militia on guard duty at that time. And the strategic importance was confirmed on the 19th of June when contingents of Confederate A. P. Hillís command working out of Romney, attacked the militia guard and destroyed the railroad bridge, cutting off rail communication from Cumberland to the west."
There is the Union unit "50th Maryland Militia" they lost 1 flag.
I doubt this was the "first" Union flag captured in the east, but in the OR 2 this is the first reported Union flag captured in the east.
Anyone know what that flag would have looked like?
Have a good morning,