U.S. Code - GPO
Access the US Code on its official govinfo site, maintained by the Government Printing Office (GPO).
U.S. Code - Legal Information Institute
Access the US Code on Cornell Law School's Legal Information Institute site, which has been providing open access to law since 1992.
U.S. Code - Office of the Law Revision Counsel
The US Code is prepared by the Office of the Law Revision Counsel of the US House of Representatives. The Counsel also presents the Code online at the above link.