In Abrams v. U.S., the Supreme Court in 1919 upheld the convictions of
several individuals under the 1918 Sedition Act for distributing leaflets
opposed to U.S. intervention in the Russian civil war involving the
Bolsheviks.
Lamont v. Postmaster General (1965) used the First Amendment to invalidate
a federal law allowing the Postmaster General to regulate communist
propaganda through the mail.
