What's in the Census?

1790 ~ Name of the head of family; profession or occupation; number of free white males of 16 years and up; number of free white males under 16; number of free white females; number of all other free persons; number of slaves.

1800 ~ Name of head of family; number of free white males under 10 years, 10 and under 16, 16 and under 26, 26 and under 45, 45 and up; same as above for free white females; all other free white persons except Indians not taxed; number of slaves.

1810 ~ Name of head of family; number of free white males under 10 years, 10 and under 16, 16 and under 26, 26 and under 45, 45 and up; same as above for free white females; all other free white persons except Indians not taxed; number of slaves.

1820 ~ Name of head of family; number of free white males under 10 years; 10 and under 16; free white males between 16 and 18 years (this sometimes resulted in a double-count);16 and under 26; 26 and under 45; 45 and up; same as above for free white females; all other free white persons except Indians not taxed; number of slaves.; number of foreigners not naturalized; number of persons engaged in Agriculture, Commerce, and Manufacturing; male and female slaves and free colored persons under 14 years, 14 and under 26, 26 and under 45, and 45 and up; all other free persons, except Indians not taxed.

1830 ~ Name of head of family; number of free white males in 5-year age groups to 20, 10-year age groups from 20 to 100, and 100 years old and over. Same as above for free white females. Number of slaves and free colored persons in six age groups (males and females, under 10, 10 and under 24, 24 and under 36, 36 and under 55, 55 and under 100, over 100); number of deaf and dumb (under 14, 14 to 24, 25 years and up); number of blind; number of foreigners not naturalized

1840 ~ Name of head of family; number of free white males in 5-year age groups to 20, 10-year age groups from 20 to 100, and 100 years old and over. Same as above for free white females. Number of slaves and free colored persons in six age groups (males and females, under 10, 10 and under 24, 24 and under 36, 36 and under 55, 55 and under 100, over 100); number of persons in each family employed in each of the following occupations: mining, agriculture, commerce, manufacturing and trades, navigation of the ocean, and navigation of canals, lakes and rivers; number of pensioners for Revolutionary or military service and their ages; number of white persons deaf and dumb (same groups as 1830), blind, the insane and idiots (at public charge and at private charge); number of colored persons deaf and dumb, blind, the insane and idiots (at public charge and at private charge); type of schools and number of scholars; number of white persons over 20 who could not read and write.

1850 ~ For each person; name, age, sex, color. For each male over 15; profession, occupation, or trade. For all free persons; value of real estate owned; place of birth of each person; whether married within the year; whether attended school within the year; whether unable to read and write for persons over 20; whether deaf and dumb, blind, insane or idiotic, pauper or convict.
Supplemental schedules for slaves. For each owner: slave's age; sex; color (B, M); fugitive from the state; number manumitted; deaf, dumb or idiotic.

1860 ~ Name; age; sex; color. For each male over 15; profession, occupation, or trade; value of real estate; value of personal estate (personal property); place of birth; whether married within the year; whether attended school within the year; for persons 20 years old and over whether able to read and write; whether deaf and dumb, blind, insane or idiotic, pauper, or convict.

Supplemental schedules for slaves. For each owner: slave's age; sex; color (B, M); fugitive from the state; number manumitted; deaf, dumb or idiotic; number of slave houses.

1870 ~ Name; age at last birthday; sex; color; occupation; value of real estate; value of personal estate; place of birth; whether father was foreign born; whether mother was foreign born; month of birth if born within the year; month of marriage if married within the year; whether attended school within the year; literacy; whether deaf and dumb, blind, insane or idiotic; male citizens 21 and over; number of males over 21 with right to vote.

1880 ~ Address; name; color, sex, age prior to June 1st; month of birth if born in census year; relationship to head of family; marital status; whether married within the year; profession, occupation or trade; number of months unemployed; whether person is sick or temporarily disabled so as to be unable to attend to ordinary business or duties; if so, what is the sickness or disability; whether blind, deaf and dumb, idiotic, insane, maimed, crippled or bedridden; whether attended school within the year; ability to read and write; place of birth of person, father, and mother.
Soundex indexing available for all states, but only for households with children 10 years old and under.

1890 ~ Almost all of the general schedules were destroyed by fire in 1921. Schedules for small parts of Alabama, District of Columbia, Georgia, Illinois, Minnesota, New Jersey, New York, North Carolina, Ohio, South Dakota, and Texas remain. Content was similar to that of the 1900 census.
Supplemental schedules for Union veterans of the Civil War and their widows survive for part of Kentucky and the states LA, ME, MD, MI, MN, MO, MT, NE, NV, NH, NJ, NM, NY, NC, ND, OH, OK, OR, PA, RI, SC, SD, TN, TX, UT, VT, VA, WA, WV, WI, WY, WASHINGTON DC

1900 ~ Address (street and house no. in large cities); name; relationship to head of family; color or race (White, Black, Chinese, Japanese, and Indian); sex; month and year of birth; age at last birthday; marital status (single, married, divorced, widowed); number of years married to present spouse; number of children of wife; number of her children living; place of birth of person and parents; citizenship (if foreign born, year of immigration, and number of years in U.S.); citizenship status if over 21 (Alien, PA=declaration of intent filed, Naturalized); occupation for persons age 10 and over; number of months unemployed; whether attended school within the year; education (whether can read, write, and speak English); ownership of home (Owned, Rented); whether a Home or a Farm; and whether Free or Mortgaged.

Separate schedules were prepared for institutions, military establishments, and Indian reservations.
Soundex available for all states.
1910 ~ Address; name of person whose place of abode on April 15, 1910 was in the family; relationship to head of family; sex; color or race; age last birthday; marital status (single, widowed, married, divorced); number of years of present marriage; for women, number of children born and number now living; birthplace of person and parents; if foreign born, year of immigration, whether naturalized, and whether able to speak English, or if not, language spoken; occupation, industry, and class of worker (employer, employee, self-employed); if an employee, whether out of work during year; literacy; school attendance; home owned or rented; if owned whether free or mortgaged; whether farm or house; whether a survivor of Union or Confederate Army or Navy; whether blind in both eyes or deaf and dumb. Soundex available for states of: AL, AR, CA, FL, GA, IL, KS, KY, LA, MI, MS, MO, NC, OH, OK, PA, SC, TN, TX, VA, WV.
1920 ~ Address; name of each person whose place of abode on January 1, 1920 was in the family including every person living on January 1 and excluding children born since January 1; relationship to head of family; whether home is owned or rented; if owned, whether free or mortgaged; sex; color or race; age at last birthday; marital status; if foreign born, year of immigration to the U.S., whether naturalized, and year of naturalization; whether attended school since September 1, 1919; whether able to read and write; birthplace and mother tongue of person and parents; ability to speak English; occupation; industry, and whether employer or employee.
Soundex available for all states.
Birth Date ~ The 1900 census (column 7) indicates the person's month and year of birth; the 1850-1880 and 1910-1920 censuses indicate the person's age. The 1870 census (column 13) and 1880 census (column 7) indicate the month in which the person was born, if born "within the year," that is between June 1, 1869 and May 31, 1870 for the 1870 census, or June 1, 1879 and May 31, 1880, for the 1880 census. The official census day was June 1 in both 1870 and 1880, although the enumerator may have visited the household at a later date.
While the person's age is not an exact date of birth, it at least provides a figure useful for tracking the person from one census to the next and for locating the person in any other vital records.
Birth Place ~ The 1850-1920 censuses indicate the person's state or country of birth.
Marriage Date ~ The 1850 census (column 10), 1860 census (column 11), 1870 census (column 14), and 1880 census (column 12) indicate whether the person had married within the year, that is, between June 1, 1849 and May 31, 1850, for the 1850 census; between June 1, 1859 and May 31, 1860, for the 1860 census; between June 1, 1869 and May 31, 1870, for the 1870 census; and between June 1, 1879 and May 31, 1880, for the 1880 census. The official census day was June 1 in each of these census years, although the enumerator may have visited the household at a later date.
The 1900 census (column 10) and 1910 census (column 9) indicate the number of years of marriage for each married person.
Number of Children ~ The 1900 census (column 11) and 1910 census (column 10) indicate how many children were born to each woman. The 1900 census (column 12) and 1910 census (column 11) indicate how many of those children were still living.
Immigration ~ The 1900 census (column 16), 1910 census (column 15), and 1920 census (column 13) each indicate the person's year of immigration to the United States. This information should help in locating a ship passenger arrival list.
Naturalization ~ The 1870 census (column 19) has a check mark for "Male Citizens of the U.S. of 21 years of age and upwards." If the person was a foreign-born citizen, this means that he had become naturalized by 1870. The 1900 census (column 18), the 1910 census (column 16), and the 1920 census (column 14) indicate the person's naturalization status. The answers are "Al" for alien, "Pa" for "first papers," and "Na" for naturalized.
The 1920 census (column 15) indicates the year in which the person was naturalized.
Birth Place of Parents ~ The 1870 census (columns 11-12) have check marks if the person's parents were "of foreign birth." The 1880 census (columns 25-26), 1900 census (columns 14-15), 1910 census (columns 13-14), and 1920 census (columns 21 & 23), indicate the person's parents' birthplaces.
Military Service ~ The 1910 census (column 30) indicates whether the person was a "survivor of the Union or Confederate Army or Navy." The answers are "UA" for Union Army, "UN" for Union Navy, "CA" for Confederate Army, and "CN" for Confederate Navy. These clues lead to military service and pension records; see Civil War Records and Confederate Pension Records for more information.
A word of caution: columns 30-32 are often "overwritten" with numbers like 2-1-0-0 or 6-9-0-0. These numbers are not the answers for columns 30-32, but were data summaries used by Census Bureau tabulators in Washington, DC, to compile statistical data.
Real Estate ~ The 1850 census (column 8), 1860 census (column 8), and 1870 census (column 8) indicate the value of real property (land) owned by each person. The 1900 census (column 25), 1910 census (column 26), and 1920 census (column 7) indicate whether the person owned ("O") or rented ("R") the home or farm.
The 1900 census (column 26), 1910 census (column 27), and 1920 census (column 8) indicate whether home and farm owners owned their property with a mortgage ("M") or free of mortgage ("F").
These clues should lead researchers to the county recorder's office or equivalent agency for deeds, mortgages, and property tax records.
Business Data ~ The 1850 census (column 7), 1860 census (column 7), 1870 census (column 7), and 1880 census (column 13) all indicate the person's occupation. If the answer is "farmer," the researcher should look for information about the farmer's land ownership, crops, and livestock in the agricultural census schedules. If the person was a saw or grist miller, cheese maker, or other "manufacturer," the researcher should check the manufacturing census schedules.

Agricultural census schedules exist for 1850-1880; manufacturing census schedules exist for 1820 and 1850-1880.