World War I created ethnic tensions that had been virtually non-existent in a community that had easily accommodated Anglo-Saxon and Teutonic traditions. Residents of Germanic descent retained strong ties with the old country. The University, modeled on the German university, admired and respected Teutonic educational and cultural traditions. Over a quarter of the students in the University were enrolled in classes in the Department of Germanic Languages and Literature. Yet the ties of blood and affection with England and common traditions of law, democratic institutions, language, and literature sustained a strong feeling for England.

At first most Ann Arborites agreed with President Wilson's plea to be "impartial in thought as well as action." However, the German conquest of neutral Belgium and submarine warfare made many agree with Professor Claude Van Tyne in condemning "Prussian militarism and German arrogance." In December 1914 the National Security League was founded to support universal military training, military preparedness, patriotism, and the extermination of values which were "un-American." The Ann Arbor branch under Van Tyne and William Hobbs was energetic and vigilant.

America entered the Great War to make the world "safe for democracy" in April 1917. In the first total war in history, nations mobilized the energies of whole societies, civilians and soldiers alike. Ann Arbor's military unit, Company I of the Thirty-first Michigan Volunteer Infantry, was mobilized into the Army of the United States on August 5, 1917. To the disappointment of many who cherished the independent traditions of the local company, the Army reorganized the Michigan National Guard into Company E of the 126th Infantry under the command of Captain Arthur G. Volland of Ann Arbor. They mobilized at Grayling, Michigan; trained in Waco, Texas; embarked from Hoboken, New Jersey; and arrived in France on March 4, 1918. Ann Arbor's "doughboys" tested their mettle in severe fighting in Alsace, at Château-Thierry, and in the Meuse-Argonne. Company E left Europe in April 1919 after serving in the army of occupation. Other Ann Arbor men volunteered or were drafted into regular army units.

The war also mobilized civilians, particularly women. Ann Arbor women led the work of the Red Cross and Washtenaw County Women's Committee, part of the Council of National Defense. Every woman in the city was urged to register with the committee and to volunteer time and skills to fill the places of men away at the front. Housewives observed "meatless days," "wheatless days," and "sweetless days" to conserve food. Five Liberty Loan drives were promoted by patriotic appeals. Gardening became popular as a way to aid "Uncle Sam" and as a means to beat the war-related inflation.

The war thoroughly disrupted University life. Two student naval militia units which had been organized in 1916 were quickly mobilized in 1917. Over 1,800 students joined the ROTC in the fall of 1917. Students volunteered for the armed forces as well; enrollment declined by about 1,500 from that of the previous spring and some 400 men left school during the fall term. Red Cross activities and bond drives occupied the remaining students.

In April 1918 the University acceded to a War Department request to train non-college draftees as gunsmiths, machinists, blacksmiths, carpenters, and mechanics. By November, over 2,000 men had had two months of training in Ann Arbor. Early the same year the Students Army Training Corps was initiated by the War Department. At one point that year, 3,750 men on campus were involved in military programs, placing intense strain on housing facilities. The unfinished Michigan Union was used as a barracks for 400 men and a mess hall for 4,000. A temporary mess hall for 1,900 was set up next to the Union. Waterman Gym was used as a barracks as were 35 fraternity houses.

The energy displayed by war advocates was often misdirected against anyone suspected of unpatriotic actions, words, or even thoughts. Intense anti-German feeling swept the state and nation. It became unpopular, if not unpatriotic, to play German music, to speak or read German. Enrollment in German courses in the University dropped from 1,300 to 150. In the name of the National Security League, Van Tyne attacked University employees suspected of pacifism, disloyalty, or "subversive" thought. Many citizens of German descent suffered from suspicion and anti-German propaganda. The Washtenaw Post , a local German language newspaper, was barred from the United States mail. Editor Eugene Heller advised his readers, "The day is not far distant when we loyal citizens must make ourselves ready to prove our loyalty before the court. In the meantime, endure, keep your mouth shut and hold out.

In the fall of 1918 the dread Spanish influenza pandemic struck down hundreds. The University was especially hard hit because of overcrowded, jerry-rigged housing and sanitary facilities. The first death occurred on October 6. With over 200 cases of flu in the city and many more on the campus, the city health officer, on October 16, ordered all auditoriums, churches, theatres, dance halls, and other places of public assembly closed indefinitely. Public schools were closed the next day. All members of the faculty and students were ordered to wear face masks, and local citizens were urged to do the same. The Daily Times News reported on October 18 that "The campus looks like a Turkish harem this morning with all the students and faculty members wearing their gauze masks, with President Hutchins leading the procession with a mask that looks like an Oriental rug."

The epidemic abated during November and the ban on public assembly was lifted on November 9, all theatres and movie houses having been thoroughly fumigated. The death toll was heavy; 115 persons died during October alone. About half the deaths were among local citizens, including five nurses, a prominent physician, and a hospital janitor.

Sacrifices, anxiety, and contention were forgotten on November 11, 1918, when the Armistice was announced. "Joy has been unconfined in Ann Arbor today," reported the Times News , "Practically all business in the city is suspended." Receiving the news at 3 a.m., Mayor Ernst Wurster called out the fire truck while Judge George Sample rushed to the courthouse to ring the bell. By 4 a.m. an enormous bonfire was blazing at the corner of Main and Huron. Regent Junius Beal ordered the sounding of the big whistle at the University Power Plant.

In spite of the sleepless night, the city quickly organized a gigantic parade. The city bands, student soldiers, state troops, the Colored Soldiers, the Welfare League, the Salvation Army, the Boy Scouts, city officials, and school children paraded through the city, ending on the steps of Hill Auditorium for a songfest.

Reform agitation and mobilization for all-out war had strained but not broken Ann Arbor's sense of community. Conversion to peacetime was to take more than a songfest, however. Postwar prosperity and inflation, the contraction of wartime industry, and the expansion of the University and resulting construction boom were to exert subtle yet powerful pressures. The hyperactive rhythms of ragtime were to be an apt symbol for Ann Arbor in the 1920's.