The following census indices are available through the Newberry Library's Census Index Quick Search Service.
Alabama: 1830, 1840, 1850, 1860, 1870, 1880
Arkansas: 1840, 1850 (surname only), 1860, 1870, 1880
Colorado: 1870, 1880
Connecticut: 1790, 1800, 1810, 1820, 1830, 1840, 1850, 1860, 1870, 1880
Dakota Territory: 1870, 1880
Delaware: 1810, 1820, 1830, 1840, 1850, 1860, 1870, 1880
D.C.: 1820, 1830, 1840, 1850, 1860, 1870, 1880
Florida: 1830, 1850, 1860, 1870, 1880
Georgia: 1820, 1830, 1840, 1850, 1860, 1870, 1880
Illinois: 1820, 1830, 1850, 1860, 1870, 1880; request alternative searches for 1900, 1910, and 1920 indices
Indiana: 1820, 1830, 1840, 1850, 1860, 1880
Iowa: 1850, 1860, 1870, 1880
Kansas: 1860, 1870, 1880
Kentucky: 1810, 1820, 1840, 1850, 1860, 1870, 1880
Louisiana: 1820, 1830, 1840, 1850, 1860, 1870, 1880
Maine: 1790, 1800, 1810, 1820, 1830, 1840, 1850, 1870, 1880
Maryland: 1790, 1800, 1810, 1820, 1830, 1840, 1850, 1860, 1870, 1880
Massachusetts: 1790, 1800, 1810, 1820, 1830, 1840, 1850, 1870, 1880
Michigan: 1820, 1840, 1850, 1860, 1870, 1880
Minnesota: 1850, 1860, 1870, 1880
Mississippi: 1820, 1830, 1840, 1850 (surname only), 1860, 1870, 1880
Missouri: 1830, 1850, 1860, 1870, 1880
Montana: 1870, 1880
Nebraska: 1870, 1880
New Hampshire: 1790, 1800, 1810, 1820, 1830, 1840, 1850, 1870, 1880
New Jersey: 1830, 1840, 1850, 1870, 1880
New York: 1790, 1800, 1810, 1820, 1830, 1840, 1850, 1870, 1880
North Carolina: 1810, 1820, 1830, 1840, 1850, 1860, 1870, 1880
Ohio: 1820, 1830, 1840, 1850, 1860, 1870, 1880
Oregon: 1850, 1860, 1870, 1880
Pennsylvania: 1790, 1800, 1810, 1820, 1820, 1830, 1840, 1850, 1860, 1870, 1880
Rhode Island: 1790, 1800, 1810, 1820, 1830, 1840, 1850, 1860, 1870, 1880
South Carolina: 1790, 1800, 1810, 1820, 1830, 1840, 1850, 1860, 1870, 1880
Tennessee: 1830, 1840, 1850, 1860, 1870, 1880
Texas: 1850, 1870, 1880
Utah: 1850, 1860, 1870, 1880
Vermont: 1790, 1800, 1810, 1820, 1830, 1840, 1850, 1860, 1870, 1880
Virginia: 1820, 1830, 1840, 1850, 1860, 1870, 1880
Washington (state): 1860, 1870, 1880
West Virginia: 1860, 1870, 1880
Wisconsin: 1850, 1860 (excluding Milwaukee), 1870, 1880