There were indeed many immigrants put into the war upon arrival in the US. There were also a lot of US-born men who entered the service of the North. Most of the immigrants, as I recall were of either German or Irish descent. There were some who fought for the Confederacy but the vast majority of the immigrants were put in service in the Union. "Most" of the men who fought for the Confederacy were Born & Raised in the South.

My own home state of TN was Greatly Divided. They supplied more men to the Union than most of the New England states, except for a few of the larger ones, yet supplied even more to the Confederacy. The first Secessionist vote in TN failed to pass. When Lincoln called on us to supply our share of the 75,000 troops he was raising to "Invade" the South a 2nd vote was taken & it passed overwhelmingly.

One question I would like to see answered, "IF" the only issue of this war was to "Free the Slaves" WHY was Lincoln so Dead Set against allowing the Black People to join the army & help fight their own Battle? Think extremely deep on that one before you answer, less you stick your foot so deep in your mouth you won't ever be able to get it out!

Miller/TN
I Didn't Say Everything I Said, Yogi Berra