The U.S. used a 48-star flag for 47 years until Alaska gained statehood in this year
[DOC] [TLE] 48 Star Large-Scale Parade American Flag For Sale at 1stdibs [PAR] 48 stars in dancing rows, a rare variety of antique American parade flag in a ... 
guess is that this variety may well pre-date the addition of the 47th and 48th 
states.