when was flag day voted to be a permanent holiday?

Flag Day was officially established as National Flag Day by an Act of Congress on August 3, 1949. Prior to that, Presidents Wilson (1916) and Coolidge (1927) issued proclamations observing June 14 as Flag Day, but it was not a permanent federal holiday until the 1949 law signed by President Harry S. Truman. Pennsylvania, however, has recognized Flag Day as a state legal holiday since 1937.