Per the U.S. Constitution, a federal census has been taken every ten years starting in 1790. They have all been microfilmed. Unfortunately some are too light to read and some pages were missed.
Each census is released to the public after the census is 72 years old
Both the National Archives branch office on Bannister Avenue in Kansas City and the Mid-Continent Public Library – North Independence branch have all of the rolls available for public use
For $120 per year www.Ancestry.com gives you access, via the web, to images of all census records (Note: the Johnson County, Kansas Public Library on Farley Street has five subscriptions to this service). But no indexes exist for 1860 through 1910. However, 1880 index is available at www.FamilySearch.com.
The type of information varies on each census. Pre-printed forms are available for free (click here to get the forms).
All censuses before 1850 have very little genealogical information but are useful in some cases
Alphabetical indexes by state exist in book form for all censuses up through 1860 and a few beyond that. MCPL-North Independence has most of these index books, Kansas City Public Library-downtown also has many of these index books (some which are not at MCPL-NI)
Starting with the 1880 census a special index was used. It is called the Soundex Code. These indexes are also microfilmed. See the next section for which censuses’ have Soundex Codes and how to use them. The 1910 census used a Soundex variation called the Mira Code.
Census records are notorious for errors of all types including misspellings, people skipped, mis-readings, faulty indexing, actual data is wrong, etc., etc., etc. If you cannot find someone where you expect them to be, try all other options you can think of such as spelling variations, listed under another household, listed in another town or enumeration district, etc.
Over the years several states decided to take their own state census. Books exist telling which states have censuses available for which years such as State Census Records by Ann S. Lainhart (Genealogical Publishing Co. Inc., Baltimore, 1994, $20)
Usage of Soundex Codes for Surnames
The Soundex/Mira Code is an alphanumeric coding system designed to keep together the names that sound alike regardless of their spelling. Only certain key letters are used. Vowels are ignored. The result is a letter followed by exactly three digits. Soundex codes are used to help index persons found on the federal census records beginning with the 1880 census. Utilities to calculate Soundex can be downloaded from the web.
To manually determine the Soundex code for a given surname use the following rules:
Write down the first letter of the surname
All letters following the first letter must be coded into a three-digit number using their Soundex codes. As soon as three digits are gotten, all remaining letters are ignored.
If the initial letter and the second letter have the same code then ignore the second letter
All letters with the code of zero are ignored
If two consecutive letters have the same code then the second letter is ignored
If all of the letters are used up but the three digits have not been determined then use zero for the remaining digits
Ignore surname prefixes such as: D', De, de, dela, della, Di, Du, La, Le, Van, Von
Soundex is not perfect. Consider the following:
Names starting with 'Ph' and 'F' sound alike such as: Phillips and Franklin
Names beginning with 'Ei' sound like just 'I' such as: Eisenhower and Ireland
Names from other countries become 'Americanized' such as: Tshantz became Shantz
Names with 'gh' followed by 'ou' make the 'gh' sound like the letter 'f' such as: Rough
Names with the letter 'l' proceeded by 'ou' and maybe some letter after it often make the letter 'l' silent even though the letter 'l' gets coded such as: Would, Could, Gould
Practice coding the Soundex code
Get the Soundex code for the surname JONES
Write the first letter: J
Scratch out all letters whose code are zero: 'O' and 'E'
code the remaining letters:
N code is '5': 5
S code is '2': 2
No more letters are left but need the required three digits, so fill the remaining positions with zero: 0