Public Utility Holding Company Act of 1935
The Public Utility Holding Company Act of 1935 (PUHCA), also known as the Wheeler-Rayburn Act, was a US federal law giving the Securities and Exchange Commission authority to regulate, license, and break up electric utility holding companies. It limited holding company operations to a single state, thus subjecting them to effective state regulation.
Source: Wikipedia — Public Utility Holding Company Act of 1935 (CC BY-SA 4.0)