Duplicate Signals at the Baltimore Observatory
Watercolor, ink, and pen on paper of "Duplicate Signals at the Baltimore Observatory," ca. 1818-1819, by an unknown artist. In 1797, U.S. Navy Captain David Porter (1780-1843) established a wooden marine observatory and watch tower on Federal Hill in Baltimore in order to alert merchants and ship owners of arriving ships. Around 1880, the original tower was replaced until a 1902 storm destroyed the tower. The U.S. flag, depicted top left, has twenty stars and twenty stripes. This was an unpopular design change that attempted to add a stripe for each additional state. The twenty star flag was adopted in 1818 and lasted only one year before the design was changed and thirteen stripes were restored.