There are officially 27 different versions of the American flag with the original being the first being created by the Continental Congress on June 14, 1777.
The flag has evolved and related laws to it have been amended several times its creation in 1777.
The first version of the flag while commonly believed to be the 13 stars in a round design, was actually never used by the federal government.
In the early days of America, there were no rules for how the flag should appear. Between 1777 (the first flag) and 1960(the last time the flag was changed with the additions of Alaska and Hawaii), Congress has approved several acts that changed the flag primarily by adding stars for new states, but also to send ground ruls for a design.
The Star-Spangled Banner, which was written by Francis Scott Key, became our national anthem in 1931.
The Act of April 4, 1818 made the 13 stripes and one star for each state standard and said that stars are to be added to the flag on the 4th of July following the admission of each new state.