What is Old immigrations vs new immigration?

The Old Immigration took place in the 1830's to the 1890's and primarily northern Europeans(Irish and German). The moved to America for a number of reasons, potatoe famine, revolutions, etc...

The New Immigration took place around the 1890's to about 1920 and was mostly eastern and southern Europeans ( Austria Hungary, Italy, Poland, Russia) Both Old and New saw each other as inferior to the other.