ALEXANDER DALLAS BACHE (1806-67) SIGNED CARD, “A. D. Bache”, on a 3 x 1 partly printed card “U. S. Coast Survey, Official Business, Supdt.”, by the American physicist, scientist, and surveyor who erected coastal fortifications and conducted a detailed survey to map the United States coastline. Originally a West Point graduate and an army engineer, he later became Superintendent of the U. S. Coast Survey before the American Civil War. He was professor of natural philosophy and chemistry at the University of Pennsylvania and in 1843 he was appointed as head of the U. S. Coast Survey and served for 24 years. He mapped the whole coast and built many observation stations. The card is in fine condition, with minor age toning.