Abstract
In this article, the authors describe a new data infrastructure project being developed at the Minnesota Population Center. The Integrated Spatio-Temporal Aggregate Data Series (ISTADS) will make it easier for researchers to use publicly available aggregate data for the United States over a time span that covers virtually the entire life of the nation: 1790-2012. In addition to facilitating access and ease of use, ISTADS will facilitate the use of these various data sets in mapping and spatial analysis.