United States Government Documents: The Presidency, Congress, the Courts, & Agency Regulations: Federal Register and the Code of Federal Regulations

From the National Archives.

From the GPO (Government Printing Office), Govinfo.gov.

Access to Regulations and regulatory histories.
Regulatory histories associated with a public law are compilations of Federal Register (FR) notices, proposed rules, and rules representing the complete rulemaking process associated with specific Public Laws. These histories are compiled by human researchers.
In addition to consulting the text of the Federal Register articles, researchers check such sources as the Code of Federal Regulations (CFR), the Public Law text, and, at times, the Parallel Table of Authorities and Rules.

1936 (vol 1) - .
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From the menu, select Publication Type > Administrative Codes and Regulations