User blog comment:ZanyDragon/Xenophobes/@comment-6024608-20131106072257/@comment-75.36.137.6-20131214142051

Immigrants of similar race but different culture. ie- Northern Irish who were Protestants later were against the influx of Southern Irish who were Catholics. Later large influx of Germans (saxons = white) was feared to be changing the political situation. So there was more than 'race' being involved. Even those Irish Catholics arriving  around the start of the Civil War into Northern cities didnt want black slaves being freed and emigrating north to compete for the low level jobs they had.