When the U.S. Congress needs a closer look at how federal funds are being spent, it calls upon the U.S. Government Accountability Office (GAO). Formerly known as the General Accounting Office from its creation in 1921 until its current name change in 2004, this non-partisan investigative office is nicknamed "the congressional watchdog" for its auditing responsibilities over federal agencies and programs. GAO investigations usually result in either congressional testimony or the publication of reports (or both). These reports are available online back to the agency's inception in the early 1920s, and are still commonly known as "blue books" after their former appearance in print, although they are now available only electronically. Reports & Testimony can be browsed or searched at the GAO website. The Advanced Search is recommended.
U.S. GAO reports can only be updated at the request of a member of Congress, either through legislation or via a request in a committee report. The latest edition of the House Document Reports to Be Made to Congress provides more than 15 pages of required GAO reports and their legislative authority. Researchers who find a useful, but outdated, report may be able to generate a request for an updated report by contacting their congressional representatives. Researchers might also discover that a report has been withheld from publication, due to the presence of classified agency information or other sensitive material. Earlier this month, GAO began posting title lists of restricted GAO products in order to provide greater transparency about the existence of these restricted materials. Reports which were withheld at the time of publication but later released may be found in the Advanced Search for the phrase "NI" in the report number field.
The GAO may also be familiar to legal researchers for their extensive compiled legislative histories. Since 2009, these have been available through WestlawNext to current members of the Law School community, with the database short name FED-LH or by browsing to Statutes & Court Rules > Legislative History. The U.S. GAO Federal Legislative Histories database includes PDF copies of congressional bills, debates, committee reports, and hearings related to enacted laws from 1921-1995.
Duke's research guide to Federal Administrative Law provides sources for background information on federal agencies and offices like GAO; the library guide to Federal Legislative History offers additional resources for locating compiled legislative history publications. For additional help with accessing GAO publications on a topic, or GAO compiled legislative histories, be sure to Ask a Librarian.