He held this position for the next four years, where he was co-author of 13 soil survey reports covering the states of Illinois, Iowa, Kansas, North Carolina, and Ohio.
[4] He served as chairman of a committee of 15 people tasked with creating a more uniform system of nomenclature and classification for soils in the United States and Canada.
[5] Coffey had resigned from the Bureau in 1911 to join the Ohio Agricultural Experiment Station,[2] and it would remain for Curtis F. Marbut to bring Dokuchaev's ideas to prominence.
[6] Coffey was awarded a Ph.D. in geology from the George Washington University in 1912 with a thesis titled A Study of Soils in the United States.
He published his last article in the Journal of the American Society of Agronomy in 1916, leaving soil science for a business career in order to be closer to his family.