Why did immagration to the US increase after the 1820s?

Answer 1

Actually there was very little Immigration to the US before the 1840s. Up to that time, even the busiest years for immigration saw no more than about 30,000 new arrivals. The first great wave was the Irish in the 1840s, fleeing the potato blight in Ireland that resulted in the death from starvation of a third of the Irish population. Just after that began there was another wave of refugees fleeing from the failed wave of revolutions which had swept Europe in 1848. The Irish were the first Catholics to come to the US in large numbers. After the Civil War there were many more Catholics among the growing tide of immigrants from southern and eastern European nations. Few had come to America from those areas before the Civil War. They came when they did becasue word had spread that a man could get land to farm, cheaply or even for free, in the American west, and there were other jobs that a man could get. So these people came for a chance at a better life than they could ever hope for where they were born. Chinese laborers were also brought in to work on the transcontinental railroads, who later lived in "Chinatowns" in Los Angeles and San Francisco, and other western cities.