He assumed several roles within the federal government, and served as president of the North Dakota Agriculture College from 1921 to 1929.
Coulter started working for the federal government in 1910, leading the U. S. Census of Agriculture.
He helped establish the system of banks and credit unions for rural use under the provisions of the Federal Farm Loan Act.
Coulter was designated an inaugural fellow of the American Statistical Association in 1914, and returned to academia in 1915, as dean of the agricultural college at West Virginia University, and led the school's experimental station.
He was later appointed president of the North Dakota Agriculture College, serving from October 1921 to July 1929, when Herbert Hoover named Coulter the chief economist of the United States Tariff Commission.