What 1777 measure first described the official design of the United States flag?

The 1777 Flag Resolution first described the official design of the United States flag.

The Second Continental Congress approved the measure on June 14, 1777. It called for 13 alternating red and white stripes and 13 white stars on a blue field, representing the 13 United States and a new constellation.

The resolution did not specify how the stars should be arranged, how many points they should have, or which stripe should be on the outside. As a result, early flags varied considerably, and the familiar circular arrangement associated with the Betsy Ross flag is not required by the original wording.

Later legislation changed the flag as new states joined the Union. The Flag Act of 1818 restored the number of stripes to 13 while adding stars for new states. The current 50-star design dates from 1960.