I am searching for information on why British men went to fight in the American Civil War 1861-1865? It seems that a lot of men from different countries went to America to fight in this war.

Samuel Midgley was born c 1843 in Yorkshire. He was only 18 when he enlisted. He fought for the Union in the 70 New York Regiment (infantry) until 1864 when he chose not to reenlist. He sent some leters back to his parents describing battles and his opinions on slavery and his time as a parole prisoner. I have found the American Civil War soldier and sailor search website and located his basic details there.

I cannot find when Samuel arrived in America and when he returned home. He married Sarah Ann Priestley and they had a daughter Clara in 1875 in Leeds England. The family moved to Australia in 1877 and Samuel died in 1888.

Are there any enlistment records for this war?

Any help to educate me in this time in history would be very much appreciated.
Kind regards Narelle