"The United States Government is the largest publisher in the world. Every day the U.S. Government issues congressional bills, laws, regulations, presidential documents, studies, and more on a variety of topics. The Federal Depository Library Program (FDLP) was established by Congress to ensure that the American public has access to its Government's information. The Federal Depository Library Program (FDLP) is administered by the U.S. Government Publishing Office (GPO).
Since 1813, select U.S. Government documents have been made available throughout the United States and its territories to designated libraries. These designated libraries are called Federal depository libraries.
As members of the FDLP, depository libraries play a prominent role in providing Federal Government information to the public. FDLP libraries collaborate on a local and national level to provide informed access to both historical and current Federal Government resources distributed through the FDLP and deposited in libraries across the country.
Anyone can visit Federal depository libraries and use the Federal depository collections which are filled with information on careers, business opportunities, consumer information, health and nutrition, legal and regulatory information, demographics, and numerous other subjects.
The authority for the Federal Depository Library Program (FDLP) and the legal obligations of designated Federal depository libraries are found in 44 United States Code §§1901‐1916."
From FDLP Basics, published 2-11-13 and updated 12-18-14