Answer:
The decade between 1851 and 1860 had the highest number of immigrants.
Step-by-step explanation:
1820-1829 128,502
1830-1839 538,381
1840-1849 1,427,337
1850-1859 2,814,554
1860-1869 2,081,261
1870-1879 2,742,287
1880-1889 5,248,568
1890-1899 3,694,294
1900-1909 8,202,388
1910-1919 6,347,380
1920-1929 4,295,510
1930-1939 699,375
1940-1949 856,608
1950-1959 2,499,268
1960-1969 3,213,749
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