Knox College's service flag is displayed on Old Main. The image was taken some time near the end of the war. The number 642 represents the number of Knox men serving in the armed forces during the war (the final number was 660).
Imitations of shell holes were created on Willard Field as part of the S.A.T.C.'s drilling ground behind Old Main on Willard Field. Old Main is visible on the left side of the photograph.