The U.S. Information and Educational Exchange Act of 1948 (Public Law 80-402), popularly called the Smith–Mundt Act, is the basic legislative authorization for propaganda activities conducted by the U.S. Department of State, sometimes called “public diplomacy”. The act was first introduced by Congressman Karl E. Mundt (R-SD) in January 1945 in the 79th Congress. It was subsequently passed by the 80th Congress and signed into law by President Harry S. Truman on January 27, 1948.

The Smith-Mundt Modernization Act of 2012, which was contained within the National Defense Authorization Act for Fiscal Year 2013 (section 1078 (a)) amended the United States Information and Educational Exchange Act of 1948 and the Foreign Relations Authorization Act of 1987, allowing for materials produced by the State Department and the Broadcasting Board of Governors (BBG) to be available within the United States.

Section 501(a) of the Act (care of the Voice of America Web site) provides that

information produced by VOA for audiences outside the United States shall not be disseminated within the United States … but, on request, shall be available in the English language at VOA, at all reasonable times following its release as information abroad, for examination only by representatives of United States press associations, newspapers, magazines, radio systems, and stations, and by research students and scholars, and, on request, shall be made available for examination only to Members of Congress.

U.S. Congressional Amendments to 1948 Act
en.wikipedia.org/wiki/Smith%E2%80%93Mundt_Act#U.S._Congressional_Amendments_to_1948_Act