Goodnow took up his teaching in October 1884 at Columbia, giving some instruction in History as well as in United States Administrative Law.
Made Adjunct Professor in 1887, Goodnow became Professor of Administrative Law in 1891, and in 1903 Eaton Professor of Administrative Law and Municipal Science. He became the first president of the American Political Science Association in 1903. Governor Theodore Roosevelt made him a member of the commission to draft a new charter for Greater New York, and President Taft chose him as a member of his Commission on Economy and Efficiency.
In October 1912 he accepted, on the recommendation of the Carnegie Endowment for International Peace, the commission of constitutional adviser to the Chinese Government which took him to China in March 1913. During the years 1913–1914 he served as legal adviser to the Yuan Shikai government in China. Yuan had hired Goodnow at the recommendation of Charles Eliot, a former president of Harvard University, and had tasked him with drafting a new constitution. Between 1913 and 1915, Goodnow wrote two versions of the constitution. The first effectively made Yuan president for life, and granted him sweeping powers over the budget and foreign policy. The second version, completed in 1915, would have made Yuan emperor had he not died soon thereafter.[1][2] Goodnow became known for his assertion that the Chinese people were not mature enough for a democratic form of government—a position that was later utilized by Yuan, as he attempted to proclaim himself the Emperor of China in 1915-6.
In 1914 he became the third president of Johns Hopkins University. At Hopkins, he is best remembered for his attempt to eliminate the bachelor's degree by cutting the first two years of undergraduate work. Called the Goodnow Plan or New Plan, students would have entered Hopkins after two years of study in other universities and would have worked toward an advanced degree, bypassing the bachelor’s degree. Although briefly implemented, the plan failed, largely because of the difficulty of persuading enough students to transfer to Hopkins halfway through their college education.[3] The plan was attempted again in substantially the same form, in the early 1950s, under President Detlev W. Bronk, meeting with the same lack of success. Known as a good financial manager, Goodnow greatly increased the university’s income during his fifteen-year presidency. Goodnow is considered an important early scholar in the field of public administration and administrative law, as well as an expert in government. Goodnow argued for the centrality of law in public administration. (Other public administration theorists have argued that other non-legal values ought to guide civil servants.)[4]
Goodnow resigned the Johns Hopkins University Presidency in 1929 and was succeeded by Joseph Sweetman Ames, but thereafter frequently gave graduate lectures in his special subjects. He was for some time a regent of the University of Maryland and a member of the Board of School Commissioners of Baltimore.