The United States adopted its current 50-star flag design in 1960.
The design has 13 horizontal red-and-white stripes representing the original colonies and 50 white stars representing the states. Hawaii's admission to the Union in August 1959 created the need for a 50-star version, which became official on July 4, 1960.
Alaska had joined the Union earlier, in January 1959, producing a short-lived 49-star flag. The flag therefore changed twice in quick succession as the nation's two newest states entered the Union.
The first congressional flag resolution, adopted on June 14, 1777, specified 13 stripes and 13 stars but did not dictate a particular star arrangement. In 1818, Congress restored the stripes to 13 and required a new star for each new state. The flag's star field has changed repeatedly, while the 13-stripe symbolism has remained stable since 1818.