This site is the primary repository of data collected by the American Institutions Project. The components of this project are (1) data on every statute passed between 1877 and 1994, including estimates of their significance; (2) issue codings for every roll call in the U.S. House of Representatives and Senate between 1877 and 2011; (3) aggregate and issue-specific ideal point estimates for this period. Coding for this project was begun by John S. Lapinski and Ira Katznelson, financed by NSF Grant SES 0318280; it was subsequently expanded by David A. Bateman.