I determined which flag is in the photo by the Era of the Postcard.  Undivided back postcards were printed from 1901 - 1907.  The 45 star flag in place from July 4, 1896 – July 3, 1908

postcard size: 3.5" x 5.5"

Domestic Shipping Options

Economy Shipping - sent in rigid paperboard envelope 

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First Class sent in rigid paperboard envelope 

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International Shipping Options

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Global Shipping Program (GSP) - sent in rigid envelope 

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