 Complete the following phrase:  After 1820 immigration gradually increased. For the first time federal records, including ship passenger lists, were kept for immigration. Total immigration for the year 1820 was 8,385, gradually building to 23,322 by 1830, with 143,000 total immigrating during the decade. From 1831 to 1840 immigration increased greatly, to 599,000 total, as 207,000 Irish, even before the 