After the civil war, where did most new immigrants to u. s. come from

During the 1870s and 1880s, the vast majority of these people were from Germany, Ireland, and England--the principal sources of immigration before the Civil War.

*** Note I am not 100% sure that this answer is completely correct. this is just my best effort to help.

I believe that most of the immigrants came from Germany and Ireland. 

Yes you are cute answer theories to explain the colonization of the new world the last great habitable landmass to be occupied by humans focus on the bering land bridge, or beringia, which emerge by siberia and alaska the last ice age.