The United States Army did not have an established medical corps when the country entered World War I in 1917. The military was ill-prepared to deal with the physical and psychological injuries of trench warfare, and the first conflict in which deadly gases were used as a weapon. As American casualties increased, the Army rapidly produced a hospital system based on the French and English war model in use for the past three years. At great risk, stretcher-bearers moved the wounded from the battlefield, and horse-drawn or motorized ambulances rushed them to mobile field hospitals for emergency treatment. From there, trains and road convoys transported the severely injured to ships headed for England, or large base hospitals located near the French coast.

Across the United States, base hospitals were quickly mobilized at universities and civilian hospitals. In October 1917, the American Red Cross authorized their Northwest Division to organize a base hospital in Seattle, providing the local Chapter raised $50,000 to equip the unit. The Seattle Girls’ War Work Association, headed by Gladys Waterhouse and Katherine Kittinger, organized a fund raising bazaar at the Seattle Arena Hippodrome during the week of December 16-25, 1917. Over $100,000 was raised, $50,000 of which was turned over to Red Cross Headquarters in Washington D.C. for the purpose of establishing Base Hospital No. 50. The Seattle unit became the last base hospital authorized by the War Department for the Red Cross.

Base Hospital No. 50 was created at the University of Washington, under the support of President Henry Suzzallo. On October 25, 1917, noted Seattle physician Dr. James Beaty Eagleson, already a major in the Army Medical Reserve, was appointed director of the base hospital. The unit was mobilized on March 27, 1918 at Fort Lawton, Washington.

The Base Hospital unit consisted of medical staff, nursing staff, and civilian enlistees without previous medical experience. Personnel included 26 officers from the Army Medical Corps, 150 enlisted men and 64 nurses, later increased to 100. On April 6, 1918, the organization was transferred to Camp Fremont, California, where it received three months of additional training. The main group reached the hospital facility in Mesves sur Loire, France on August 6, 1918. Many of the wooden barrack wards were still unfinished. On August 15, the first consignment of seriously injured patients arrived. The capacity of the hospital was 1,000 beds, with a crisis expansion to 1,950. Base Hospital No. 50 was a special facility for compound fractures and joint injuries. The total number of sick and wounded treated was 7,399, with 1,135 surgical operations.

Base Hospital No. 50 was closed on January 20, 1919. The hospital personnel arrived in New York April 20, 1919, and were demobilized at Camp Lewis, Washington. Shortly after the war, the personnel of Base Hospital No. 50 formed a veteran’s group, and they continued to meet until around 1986.