As of 2014, there are 50 five-pointed stars on the flag of the United States of America, one for each state. The stars represent the stars in the heavens, symbolic of the aspirations of the United States.
A new white star is added to the blue field every time a new state joins the union. In today's flag, these stars are arranged in nine rows, alternating six and five stars in each row. However, earlier arrangements of the stars varied. The original flag of the United States held a circle of 13 stars, one for each original state.
When new states join the United States, the flag is officially changed on July 4 of the year after the state is added. As of 2014, there have been 39 versions of the flag, and almost all of the changes made have been to the star field.