American participation in World War I did not dampen the level of participation in the Rand School. The institution saw a record enrollment of about 4,000 students for one or more classes in the 1918 academic year and an additional gain of up to 50% was projected by Executive Secretary Bertha Mailly for 1919-20. Of these all but 30 were part-time students, with an additional 70 taking a full complement of courses spread out over a longer period, attending classes only 2 or 3 nights a week.