Legislative Branch (Article I of the US Constitution):

United States House of Representatives

www.house.gov

United States Senate

www.senate.gov

Unites States Congress Legislative Information

www.congress.gov

Executive Branch (Article II of the US Constitution):

The White House

www.whitehouse.gov

United States Department of Justice

www.justice.gov

Office of the Federal Register

www.archives.gov/federal-register

Code of Federal Regulations

www.ecfr.gov