James Craig Watson
He was the first foreigner to become director of an American observatory, serving as director of Detroit Observatory (at the University of Michigan) from 1854 to 1863. He played a major role in establishing the study of astronomy in the United States at a time when the only other serious faculty was run by Benjamin Peirce at Harvard University. He introduced the teaching of rigorous German analytical methods and trained a number of students who went on to further American astronomy, including Asaph Hall and James Craig Watson (the latter succeeded him as director of Detroit Observatory). In addition, Charles Augustus Young learned German astronomical methods from Brünnow although he did not attend the University of Michigan.