sentences:  After the United States entered World War I in 1917, the federal government granted the Academy a junior unit of the Reserve Officer Training Corps.For a time all male students were require to have served in the corps of cadets, and all those in grades nine through twelve are formally enrolled in the army Junior ROTC program, but it is no longer required.Girls have also participated in military training on an optional basis since 1973 when two students, Mary Shepard and Karen Stubbs led the development of the first female platoon.