In 1859, Weitzel returned to West Point as Assistant Professor of Civil and Military Engineering, working under professor Dennis Mahan. During home leave in 1858, he had become engaged to Louisa C. Moor of Cincinnati, and they married at Cincinnati's German Lutheran Church on November 3, 1859. However, three weeks later her skirts caught fire as she prepared Thanksgiving dinner, and despite Godfrey's efforts to douse them, she suffered severe burns and died within hours. Weitzel accompanied her body to Cincinnati. The grief-stricken widower was granted eight months leave, including permission to travel to Germany.