The United States Census is a marvelous tool for genealogy research. It has been taken every 10 years from 1790 through 2000, and in some years the census lists not only names, ages and birthplaces, but also give the relationship of individuals in a household, when ancestors came to the U.S., if and when they were naturalized, and other important pieces of information.
Those looking for their Italian roots will be most interested in censuses taken between 1850 and 1930 for a few reason, foremost because this is the period that saw the biggest Italian immigration into the United States, but also because the census from 1790 through 1840 only named the head of the household, everyone else in the household was just listed in categories. For example — 2 females over 16, 1 male under 16 and finally because censuses after 1930 are still confidential and the information they contain is not open to the public.
The census from 1850 through 1930 lists each member of the household and usually gives the relationship to the head of the house. It also gives age (later years give birth month and year) and place of birth (usually just the state or foreign country).Note that unfortunately the 1890 census was almost totally destroyed by fire so there is a 20 year gap between 1880 and 1900.
I suggest that you begin your search with the 1930 census and work backward. you will probably have more information on relatives who were alive in 1930 than earlier and you can work your way backwards as more names are found and linked together. For instance I found almost every branch of my family in the 1930s census, and the following information about them:
The Santora's names all listed: Nicholas, Grace, Anthony, Jerry, Madeline, Filimina, Agnes, Angelina, Lucy, and Dorothy, as well as Loglio's (sic - should be Lovaglio) Rocco, Olga, Angelina, Ralph, and Nicholas, all living at 28 Floyd Street, an apartment building which Nicholas Santora owned in Brooklyn NY and that Rocco was renting his apartment there for $20/month. I also found a list of all their occupations: Nicholas was a baker at an unnamed bakery Anthony and Jerry are listed as upholsterers Madeline, Filimina, Agnes, and Angelina are all listed as seamstresses with different specialities; and Rocco Lovaglio's occupation was a sole cutter at a shoe factory.
The DeVito's: Antonio, Carmella, Edward, and Michael can also be found on the 1930 census, living at 657 Wythe Avenue Brooklyn NY an apartment which they rented for $30/month. The occupation listed for Antonio, Michael and Eddie was Barber, and their industry is listed as "own shop".
Aurelia DeVito was married by 1930, and appears in the census as "illegible" Tedone, and is incorrectly listed as a male. "his" "wife" is listed as Fulvatore (maybe Salvatore?)
I also found my mother's family. Leonard C Butcher, Alice Atwood, Laura and Bernice Atwood appear on the 1930 census At 4123 Whitman Ave, Seattle City, WA. It looks as if at the time of the census they were living in different apartments in the same building so perhaps this is is how they met. Alice is listed as a factory worker and Leonard as the foreman of a lumber yard, Alice was born in Minnesota, Leonard in England. Both the girls were born in Washington State Leonard's immigration year appears to be 1914, and he was not Naturalized as of 1930. All this I know only from the census listing.
My wife's Grandfather Henry H. Atkins is also in the 1930's census. His age was 28, his wife is listed as Jese M. 34, Children Janice11 mo and Henry H. Jr. 2 and stepdaughter Millicent Wigfield 11 also appear on the 1930 census all living along the Baltimore Pike in Allegheny MD. Henry's occupation is listed as a machinist at a stub mill.
So you see, there is a wealth of information that can be gleaned from the census.
Individuals are listed in a census by year, then state, then county, and district. You must know the state to begin a search. Within the 1850–1930 period, unless you know a fairly exact location, the most important consideration is the existence of an index. In an earlier posting about the Ellis Island ship manifest archive I recommended searching on relatives with unusual names first. The strategy is still a sound one. You can also take advantage of Soundex Indexes. See my post on the Soundex System.
The 1920 census has been indexed by the government by surnames within a household using the Soundex system. The 1900 census also has a Soundex index for all states. The 1910 census has only been indexed for the following states: Alabama, Arkansas, California, Florida, Georgia, Illinois, Kansas, Kentucky, Louisiana, Michigan, Mississippi, Missouri, North Carolina, Ohio, Oklahoma, Pennsylvania, South Carolina, Tennessee, Texas, Virginia and West Virginia. Unfortunately, this omits some of the most populous states such as New York and New Jersey. The Soundex index to the 1880 census only covers households that had children under the age of 10. The Soundex indexes were created by copying the original handwritten entries from the census. The index cards for some years are also handwritten. This means that you are reading the handwriting of one person who wrote down what he or she thought another person had written. Needless to say, errors can occur. In all indexes, if you do not find the name you are looking for, you should look under other letters that might be written similarly — F for T, S for L, etc. You should also assume that an L (4) and a T (3) within the name might have been mistaken and search other Soundex codes. Be alert for unexpected spellings of the name you are looking for. Earlier Censuses and Printed Indexes exist, but are beyond the scope of this posting. The Family History Library in Salt Lake City has an extensive collection, but they do not circulate.
Many states also had their own census, sometimes at more frequent intervals. There are census returns in other countries also. Canada and Great Britain have census for every 10 years since 1841. There are not nearly as many indexes for these census as for the U.S. ones, but there is an online index of the 1871 census for Ontario. Because of their 100 year confidentiality rule, only 1841–1891 are open to the public. They can also be obtained from the Family History Library. No matter what area you are researching, one of the first resources you should look for is a census.
All U.S. censuses are available at the 11 offices of the National Archives. Many of the censuses are also available in many genealogy libraries and Family History Centers. All censuses are available on loan from the Family History Library in Salt Lake City through your local Family History Center. There are also many sources online for your search, most require a small membership fee to access them.