The original caption of this image is "State Normal School, Main Building, De Kalb, Ill.," but this school is now known as Northern Illinois University, and the "Main Building" is known as Altgeld Hall. NIU changed its name several times in its early years, but the last time it has "Normal School" in its name was 1921, when its name became "Northern Illinois State Teachers College." Based on these women's fashions, do you think it could be the 1910s or early 1920s? By skirt length I would have guessed a little later, although I don't profess to be an expert - and there seems to be some variety among these ladies. As one final note, check out the bashful woman in the foreground. She's my favorite.