Tannenbaum would keep up his interests in prison reform even while an undergraduate at Columbia University. In 1917, he testified before the New York State Prison Commission on conditions at Clinton Penitentiary in upstate New York, revealing various inhumane and brutal conditions (Leary, 1917). In fact, in a letter to the editor of the Atlantic Monthly , Tannenbaum wrote (Box 4, Folder S(1), letter of Jan. 10, 1920 to Mr. Sedgwick):

The publicity given to prison reform has produced a popular impression that our prison system throughout the country has undergone very important changes. This it seems to me, is, to say the least not quite true. I am not denying that a change for the better has taken place in some of the prisons. Unfortunately, however, that change is rather isolated and exceptional.