In the U.S. Code, one finds the following “independent establishments of the executive branch” mentioned: (1) the National Center for Productivity and Quality of Working Life (15 USC 2411); (2) the Harry S Truman Scholarship Foundation (20 USC 2004); (3) the James Madison Memorial Fellowship Foundation (20 USC 4502); (4)
Title 39 of the U.S. Code is devoted to the U.S. Postal Service (USPS). Most laws on the USPS can be found there, though some postal laws also may be found in Title 18, and other references to the “postal service” may be found throughout the U.S. Code.
The Office of the Secretary of the Senate has a web page that provides data on vetoes and their individual histories. The web page also includes information on the process by which Congress may override a veto.