Our American flag has gone through many changes over the years. It's interesting that there weren't any 'specs' outlined until 1912:
"Until the Executive Order of June 24, 1912, neither the order of the stars nor the proportions of the flag was prescribed. Consequently, flags dating before this period sometimes show unusual arrangements of the stars and odd proportions, these features being left to the discretion of the flag maker. In general, however, straight rows of stars and proportions similar to those later adopted officially were used."