 Lamar and Shreve left Mallinckrodt and St. Louis in 1911 for northern New Jersey, where Lamar founded Lamar Chemical Works, which Shreve soon took over.At age 29, he founded Shreve Chemical Company, before becoming a chemical engineering consultant in 1919.In 1923 Shreve became the chief stockholder and president of Ammonite Company, which was then based at the Nixon Nitration Works in what is now Edison, New Jersey.