 He argued that teachers be allowed to present more symbolic exercises that taught the meaning of the principles the flag stood for, which caused conflict with organizations including the Daughters of the American Revolution that were trying to ensure that a more rigorous program of patriotism be taught in schools.In early 1918, Cooper attempted to defend the teaching of German in schools, saying, "aversion to and detestation of things German may carry us to unreasonable and reactionary limits", but relented in the face of public pressure and removed it from the curriculum that April.The following year, the board rescinded its approval of a series of history textbooks that had been deemed too pro-German, and also fired a high school teacher, Charles Neiderhauser, for an alleged lack of patriotism.