Jonathan Edward Caldwell (March 24, 1883 – November 8, 1955) was a Canadian-American self-taught aeronautical engineer who designed a series of bizarre aircraft and started public companies in order to finance their construction. None of these was ever successful, and after his last known attempt in the later 1930s he disappeared, apparently to avoid securities fraud charges. His name was later connected with mythical German flying saucers, and he remains a fixture of the UFO genre.
Caldwell was born in Hensall, Ontario, Canada, the fifth son (and one of twelve children) of William Thomas Caldwell (1848–1930) and Sarah Alice Chamberlain (1852–1933).[1] He moved to the United States in 1910 and attended Oregon State College, from 1912 to 1913, majoring in mechanical engineering. He formally emigrated from Canada in 1914 and applied for U.S. citizenship in 1915, while working as a farmer in Montana.[2] In the 1920s, according to statements he made later in life, he became interested in aviation and began to study the fundamentals of aerodynamics.[3]