Renowned ornithologist Elliott Coues, known for his pathbreaking written works such as Key to North American Birds, had established the American Ornithological Union. He had also previously worked as an army surgeon and later taught anatomy. He was also briefly part of the Theosophical Society, though he later lost interest.
Astronomer Charles Augustus Young is best known for his research on the flash spectrum of the Sun. He penned several significant books on astronomy, such as General Astronomy, and taught at Princeton University, too. He had also been part of the 85th Regiment of Ohio in the Civil War.