Data Update: IPUMS NHGIS Now Includes 1970 Block Boundaries

Posted: 4/25/2025 ()

IPUMS NHGIS now includes 1970 census block boundaries! This is the first-ever release of digital data for these areas, extending our collection of block boundaries to span six censuses across five decades. This release covers all or part of 21 metro areas, including the cores of 7 of the 8 largest metros in 1970 — New York, Chicago, Philadelphia, Detroit, San Francisco-Oakland, Washington, Boston — as well as Dallas-Fort Worth, Minneapolis-St. Paul, Milwaukee, and Sacramento. To learn more and to access the data, see the 1970 Block Boundaries page.