Census 2000:

The 2000 United State Census lists 15,725,555 persons of Italian heritage. States with the largest Italian-American communities include:

1. New York- 2,737,146
2. New Jersey- 1,503,637
3. California- 1,450,884
4. Pennsylvania- 1,418,465
5. Florida- 1,003,977

Here is a complete breakdown of the Italian-American population, by state:

State Italian-
American population
Italian-
Americans as a percentage of total
United States 15,723,555 5.6
Alabama 56,220 1.3
Alaska 17,944 2.9
Arizona 224,795 4.4
Arkansas 34,674 1.3
California 1,450,884 4.3
Colorado 201,787 4.7
Connecticut 634,364 18.6
DC 12,587 2.2
Delaware 72,677 9.3
Florida 1,003,977 6.3
Georgia 163,218 2.0
Hawaii 22,094 1.8
Idaho 34,553 2.7
Illinois 744,274 6.0
Indiana 141,486 2.3
Iowa 49,449 1.7
Kansas 50,729 1.9
Kentucky 62,383 1.5
Louisiana 195,561 4.4
Maine 58,866 4.6
Maryland 267,573 5.1
Massachusetts 860,079 13.5
Michigan 450,952 4.5
Minnesota 111,270 2.3
Mississippi 40,401 1.4
Missouri 176,209 3.1
Montana 28,031 3.1
Nebraska 42,979 2.5
Nevada 132,515 6.6
New Hampshire 105,610 8.5
New Jersey 1,503,637 17.9
New Mexico 43,218 2.4
New York 2,737,146 14.4
North Carolina 181,982 2.3
North Dakota 5,328 0.8
Ohio 675,749 6.0
Oklahoma 49,970 1.4
Oregon 111,462 3.3
Pennsylvania 1,418,465 11.6
Rhode Island 199,077 19.0
South Carolina 81,377 2.0
South Dakota 7,541 1.0
Tennessee 94,402 1.7
Texas 363,354 1.7
Utah 57,512 2.6
Vermont 38,835 6.4
Virginia 257,129 3.6
Washington 191,442 3.2
West Virginia 69,935 3.9
Wisconsin 172,567 3.2
Wyoming 15,286 3.1

More population information on American ethnic groups is available at the Census page.