U.S. Copyright law is found in Title 17 of the United States Code, which is one of the titles that has been enacted into positive law by Congress - meaning that Title 17 is legal evidence of the law in all U.S. courts.
The United States Code can be found online at the website of its publisher, the Office of the Law Revision Counsel of the United States House of Representatives
The U.S. Code is also available online at GovInfo.
Annotated versions of the United States Code are published by West (United States Code Annotated or U.S.C.A.) and Lexis (United States Code Service or U.S.C.S.) and are available online in both services. HeinOnline offers full historic coverage of the print edition of the U.S. Code, which can be useful when faced with an issue based on a previous copyright law.
Copyright Act of 1976
Copyright Amendments Act of 1992
Sonny Bono Copyright Term Extension Act (CTEA)
Digital Millennium Copyright Act (DMCA)
Family Entertainment and Copyright Act
Orrin G. Hatch-Bob Goodlatte Music Modernization Act
Copyright Alternative in Small–Claims Enforcement Act of 2020 (CASE Act of 2020)