Daniel Joseph Boorstin was an American historian at the University of Chicago who wrote on many topics in American and world history. He was appointed the twelfth Librarian of the United States Congress in 1975 and served until 1987. He was instrumental in the creation of the Center for the Book at the Library of Congress.

The librarian of Congress is the head of the Library of Congress, appointed by the president of the United States with the advice and consent of the United States Senate, for a term of ten years. The librarian of Congress also appoints and oversees the Register of Copyrights of the U.S. Copyright Office and has broad responsibilities around copyright, extending to electronic resources and fair use provisions outlined in the Digital Millennium Copyright Act. The librarian determines whether particular works are subject to DMCA prohibitions regarding technological access protection. In addition, the librarian appoints the U.S. poet laureate and awards the Gershwin Prize for Popular Song.