If you've ever riffled through your grandparents' junk drawers looking for scissors or tape, you might've found errant S&H green stamps that've probably been there since the 70s. These stamps ...

Could you have a penny worth way more than one cent? Or a quarter worth a small fortune?  A 1943 bronze Lincoln cent, a 1944 steel Lincoln cent, or a 1937-D 3-legged ...

The "Inverted Jenny," 1918, one of the rarest and most valuable stamps in the world, celebrates the first air mail in the U.S.—by depicting an inadvertently upside-down airplane. Hannah Whitaker ...