The identity of this soldier, as well as his relationship to the Coogan immigrants from Ballyloughan, is not known, but his photo is included in the Lincoln, Illinois collections.  He may be a Meany relative known to have served in the Civil War.  If his surname was Coogan, there are two possibly relevant U.S. Army records:

Thomas F. Coogan, who served three months at the rank of Private in the 69th N.Y. State Militia, Company I ("Allegiance Union"), in 1861

John Coogan, who also served three months at the rank of Private in the 69th N.Y. State Militia, Company C ("Allegiance Union"), in 1861. (See the NY Times' listing of a John Coogan in 1861.)

The New York 69th was staffed with Irish-immigrant and Irish-American volunteers.  The regiment seal displayed a harp and shamrock and the following verse: Céad míle fáilte! [A hundred thousand welcomes] Hail to the true and tried, shout their praise far and wide, Greet them once more with an Irish hurrah! Swift to charge--firm to stand, brave heart and steady hand, long live the Sixty-Ninth! Erin go bragh! [Source: New York Historical Society: http://www.nyhistory.org/ ]  Visit the NYHS web site to see a photo of the seal.