United States Census Records
Census records are among the most frequently used materials of genealogists
and family historians. From the first federal population enumeration
in 1790, the names of the heads of households have been listed on the
census, along with other information. Beginning with the 1850 census,
the names of all other members of each household were listed as well,
along with other detailed information about them. In successive decades'
censuses, more and more questions were asked and more information was
included. For example, in the 1900 census, the birthplace of each individual—as
well as that of the individual’s father and mother—was listed, an invaluable
tool for tracing the location of persons in previous censuses in other
locations.
Federal census records for 1790, 1800, 1810, 1820, 1830, 1840, 1850,
1860, 1870, 1880, 1900, 1910, and 1920 were microfilmed by the National
Archives and Records Administration (NARA) and are available for viewing
there, at larger libraries and archives with genealogical collections,
and at or through LDS Family History Centers™ (FHCs). (The 1890 census
has been almost completely lost, with only a few exceptions, as a result
of fire and water damage. (source: "The Basics
of Using Federal Census Records" by George G. Morgan read the full
article 
here
)
Census
Archives - US GenWeb
this free site has over 60,000 pages of data online
Census Records for New
England States
1830..
Free Negro Heads of Families in the United States
1880
US Census Search
search the entire 1880 census for free at FamilySearch.org
U.S. Indian Census Schedules, 1885-1940 
Search
1790-1930 Federal Censuses from Ancestry.com.
Some
Do's and Dont's with Census Records 30 useful tips to get more out
of your census research.
Clues
in Census Records, 1790-1840 tips from National Archives and Records
Administration (NARA)
Cyndis
List; US Census has links to many census resource sites
The
Soundex Indexing System work out your ancestor's soundex code here
The soundex is a coded surname (last name) index based on the way a
surname sounds rather than the way it is spelled. Surnames that sound
the same, but are spelled differently, like SMITH and SMYTH, have the
same code and are filed together. The soundex coding system was developed
so that you can find a surname even though it may have been recorded
under various spellings.|
About U.S. Census Population Schedules
includes helpful tips for specific census years
Interpreting the Tick Marks on Federal Censuses 
US Census Bureau
U.S. Federal Census Mortality Schedules Index 
(Ancestry.com) Included in the 1850, 1860, 1870, and
1880 censuses were questions regarding those who died in the twelve
months prior to the enumeration. They list persons who died between
1 June and 31 May of the year prior to the census
State Censuses:
