As explained on the site:
“This project, originally compiled by Gary Zuk, Deborah J. Barrow, and Gerard S. Gryski, was undertaken to compile a definitive database on the personal, social, economic, career and political attributes of judges who served on the United States Courts of Appeals from 1801 to 1994….The Appeals Court Attribute dataset contains information on judges who served from 1801-2000 (and partial information on judges through 2004); and, the District Court Attribute dataset contains information on judges who served from 1789-2000 (and partial information on judges through 2004).
The databases include conventional social background variables such as appointing president, religion, political party affiliation, education and prior experience. In addition, unique items are provided such as the temporal sequence of prior career experiences, the timing of and reason for leaving the bench, gender, race and ethnicity, position numbering analogous to the scheme used for the Supreme Court, American Bar Association rating, and net worth.”
The rest of the site contains equally amazing datasets on the federal court voting patterns, working papers and links to other related databases.