According to the
Flag Act of 1818, when new states are added to the union, corresponding stars are added to the flag on the following Fourth of July. So July 4th is not just the birthday of the US, but also of the 25 flags it has used since 1818. Here are some notable examples:
The 20-star flag, adopted 4 July 1818, replacing the 15-star, 15-stripe “Star Spangled Banner” of Francis Scott Key fame. One of nine US flags that lasted only one year, this flag added five stars for Indiana, Louisiana, Mississippi, Ohio, and Tennessee, and was replaced the following 4th of July by the 21-star flag recognizing Illinois statehood. Before 1912 the arrangement of the stars was not specified, allowing beautiful designs like this Great Star to circulate.
This is “ Old Glory“, the 23-star-plus-one-anchor, 10′ x 17′ flag given by the people of Salem, Massachusetts to Captain William Driver prior to his around-the-world trip commanding the brig Charles Doggett in 1831. Years later, in 1862, after keeping the flag safely hidden in Nashville during the Civil War, Driver was given permission by the Federal army to raise his flag over the capitol building, making Old Glory famous as the first US flag to fly over a former Confederate capitol. (By 1862 the US flag had grown to 34 stars, but Driver was persuasive!)
The 33-star flag adopted 4 July 1859, acknowledging the admission of the finest of the 50 states to the union.
George C. Scott portraying General George S. Patton at the beginning of the 1970 epic, Patton. The US fought both World Wars of the 20th century under this 48-star flag, adopted 4 July 1912 after the admission of Arizona and New Mexico. This was the first US flag to have an officially-mandated star pattern.
The longest serving of the 28 US flag designs, this, the current version, is often taken for granted as “the” one and only US flag. It was adopted 4 July 1960 after the admission of Hawaii, making it 55 years old today. The star arrangement of two matrices, one within the other, makes clever use of this arithmetic: 50 = 30 (the outer matrix: 5 rows of 6 stars) + 20 (the inner matrix: 4 rows of 5 stars).