He got his degree in engineering from Sheffield Scientific School but then pursued botany after he participated at some classes with Daniel Cady Eaton in Yale University.

He was accustomed with John H. Redfield and Asa Gray the later of which suggested him to join Ferdinand V. Hayden's expedition to southwest Colorado and Utah where he will use his surveyor skills as well as botanical.

Later on, he was hired at the Northern Transcontinental Survey and created a map of Adirondack region.

From 1889 to 1906 he wrote a 12-volume work called Plantae Mexicanae Purpusianae which was published in collaboration with Carl A. Purpus.

He married a fellow botanist, Katharine Layne Curran in San Diego in 1889.