Is this your guy?

Roster Source: Bates, Samuel P. (Samuel Penniman), 1827-1902.: History of Pennsylvania Volunteers, 1861-5; prepared in compliance with acts of the legislature, by Samuel P. Bates

Recruited in Huntingdon, Huntingdon County, Pennsylvania
Mustered in April 26, 1861
Biddle Guards

10th Regiment, Co. I Pennsylvania Volunteers

Captain
Henry L. McConnell

Second interesting lead is a black gentleman from KY named Anthony Beard who's wife Lizzie Beard apparently filed for a widows pension under the name of Henry L McConnell, Anthony Beard's post war alias. Seems Mr Beard was in the 125th USCT and likely spent time in Cairo IL with the unit between 1865 and 1866. Did your Major have anything to do with that unit? ( From Dyer's 125th Infantry, US Colored Troops: Organized at Louisville, Ky., from February 13 to June 2, 1865; mustered out, October 31 and December 20, 1867)

Just poking around...

John R.