Vermont became the 14th state in 1791, closely followed by Kentucky
as the 15th in 1792. The United States flag wasn't actually changed
to recognize both of them (with 15 stars and 15 stripes) until 1794.
Prior to statehood, Vermont had been an independent commonwealth and
off and on part of both New Hampshire and New York, to hear them tell
it, for over a decade. You can read much more about this here.
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Fact: Vermont is the only state in the U.S. that doesn't allow
billboards.