Thomas graduated from the University of Michigan in 1874 with a Bachelor of Arts. He taught Latin and Greek at the Grand Rapids High School for a while, after which he studied philology at the University of Leipzig in Germany in 1877/1878. His studies ended abruptly when he responded to a request from the University of Michigan to return and teach German.[1] In 1886, he became professor of Germanic languages at Michigan. In 1896, he moved to fill the same chair at Columbia University.
After his first wife, Mary J. Sutton of Lapeer, died the year they were married (1880), he married Mary Eleanor Allen of Grand Rapids in 1884. They had two children.[1]