Prior to 1970 the level of detail both in terms of topic and geographic reporting is much lower than for later years. Most files that are available are public use microdata files or files based on printed publications.

• Online Extraction Data
  • National Historical Geographic Information System (NHGIS)
    Provides online extraction tool for selected summary file variables at the national, state, and county levels for years back to 1790.
    Tract data starting in 1910 for NYC with more locations added with each new Census release.
  • Social Explorer
    Use Data & Tools then choose Browse Reports.
    Selected tables down to tracts for 1960, 50, and 40 and down to county from 1930-1790.
  • Integrated Public Use Microdata Series (IPUMS)
    At this site custom extractions of public use microdata can be done. Coverage is for all census years since 1850 except 1930.
  • Historical Census Browser
    This site provides a web-based interface to state and county data for census years 1790 through 1960. Users who wish to work with the data directly should use ICPSR Study, Historical, Demographic, Economic, and Social Data: The United States, 1790-1970. This study can be downloaded from the ICPSR website.
• Files for FTP
  • ICPSR
    ICPSR has the best collection of machine readable files for early census years. It includes Elizabeth Bogue tract data files for 1940, 50, and 60 for selected metropolitan areas (NYC available only for 1940) and states. The Bogue files are not microdata but summary data compiled from the print Census Tract reports
  • CU Data Catalog
    Two of the ICPSR studies are stored in CU Data Catalog with study number 1960, one is the public use microdata and one is tract level data that reports only on selected characteristics of a subset of the population.
• Other Online Resources
  • Selected Historical Decennial Census Population and Housing Counts
    This page contains links to a variety of sites that report early census data for a variety of geographic areas nationwide. Data may be presented in machine readable form or in PDF format.
• Spatial Data
  • National Historical Geographic Information System (NHGIS)
    Use the NHGIS Shape Finder.
    Files for tracts, counties, states, and metropolitan areas are Files Coverage of file when available starts with 1790.

Because of the limited amount of data that is available electronically, it is important to be aware of what is in print.

• Library's Decennial Census Collection
  This is a detailed list of Columbia's print and CD-ROM holdings plus links to useful Web sites and reference sources.
  Note: Selected New York City tract volumes are available in the Data Service. These include 1990, 80, 70, and 60. There is only one copy of for 1950 and it is located with Lehman's collection of census volumes in that stacks at HA 201 C3.223:950.
• Publications Specific to New York City
  • Census Tract Data on Population and Housing in New York City 1940
    HA 730 .N5 W3 - Lehman Reference
    
  • Census Data With Maps for Small Areas of New York City, 1910-1960
    HA 730 .N5 B68 1981 - Lehman Reference
    Includes not only the published census data for NYC, but also unpublished census data and special tabulation performed by the NYC Planning Dept. Levels include block, tract, and health area for 1910-1960, as well as assembly district, statistical area, and sanitation district for some earlier censuses. All data, including maps, is on microfilm (F d901) located in Lehman Library.
  • Population of the City of New York, 1890-1930.
    HA 730 .N5 C5 1930 - Lehman Reference
    317.8 N484 - Business
    AA9127 N4 C49 - Avery
    Tabular presentation of data from several censuses, both Federal and New York State, with some data actually going back to 1790.
    
  • New York City Statistics
    This is a list of print and online publications that report statistical information about New York City.
• New York State Census
  New York State conducted its own census in 1808, 1814 and 1822, though not in all counties. This link is to a CU Libraries Research Guide that describes what is available.
• Related Reference Material
  • Geographic Areas Reference Manual
    Although focused on the 1990 Census, this book provides a history of census geography and including information about areas like MCDs, CCDs, outlying areas, Indian lands, and blocks. This book is also available in print in the Data Service and in CLIO.
  • Measuring America: The Decennial Censuses From 1790 to 2000
    Contains questionnaires and instructions, plus individual histories of each census as well as a chart listing topics covered in each census year. This book is also available in CLIO.
  • 200 Years of Census Taking: Population and Housing Questions, 1790-1990 (slow to load)
    In addition to the online PDF version it is also available in print, Lehman's Collection, call number C 3.2:T 93 )
    
  • Decennial Census: General Census Monographs
    This is a list of additional publications on the subject of the Decennial Census.