In the 1840s, America population was 20 million people, with 15% of that population residing in urban areas.
1846 was the year of the great potato famine in Ireland, and resulted, in part, in a large influx of Irish immigrants to America.
The 1840s showed a marked increase in Scandinavian immigration to the United States. A large part of this group settled in Wisconsin and Minnesota.
From 1815 until the beginning of the Civil War, over five million people moved to the United States. Approximately half of these people came from England, and about 40% came from Ireland.
From 1812 until 1852, national population rose from 7 million to 23 million. Land available for settlement doubled.