With the entrance of new states into the United States after independence, new stripes and stars were added to represent new additions to the Union. In 1818, however, Congress enacted a law stipulating that the 13 original stripes be restored and that only stars be added to represent new states.
On June 14, 1877, the first Flag Day observance was held on the 100th anniversary of the adoption of the Stars and Stripes. As instructed by Congress, the U.S. flag was flown from all public buildings across the country. In the years after the first Flag Day, several states continued to observe the anniversary, and in 1949 Congress officially designated June 14 as Flag Day, a national day of observance.