Our first flag had 13 stripes, red and white, and 13 white stars on a blue field. In 1791 and 1792, stars and stripes were added for the new states of Vermont and Kentucky. So the flag had 15 stars and 15 stripes until 1818. The rules changed after that. As more states joined the union, each flag had only 13 stripes but an added star for each new state. Since the Smithsonian flag was flown at the Battle of Baltimore during the War of 1812, it has 15 stripes and 15 stars.