Where did most immigrants to the United States come from prior to the Civil War?

During the 1870s and 1880s, nearly 12 million immigrants arrived in the United States while the great majority came from Northern and Western Europe. Before the American Civil War, the vast majority of immigrants were from Germany, Ireland, and England. Half of the America's immigrants came from Ireland, where they were suffering from a massive famine. Besides, five million German immigrants settled down and bought farms in the Midwest. Asian immigrants also arrived to the US for the lure of California gold rush during those times.