The U.S. Government Publishing Office (GPO) is the Federal Government’s official, digital, secure resource for producing, procuring, cataloging, indexing, authenticating, disseminating, and preserving the official information products of the U.S. Government. The GPO is responsible for the production and distribution of information products and services for all three branches of the Federal Government, including U.S. passports for the Department of State as well as the official publications of Congress, the White House, and other Federal agencies in digital and print formats.

Source: https://www.gpo.gov/about/