 In 1873 , the cornerstone of Sage Hall was laid . This new hall was to house the Sage College for Women and thus to concretely establish Cornell University 's coeducational status . Ezra Cornell wrote a letter for posterity — dated May 15 , 1873 — and sealed it into the cornerstone . No copies of the letter were made , and Cornell kept its contents a secret . However , he hinted at the theme of the letter during his speech at the dedication of Sage Hall , stating that " the letter deposited in the cornerstone addressed to the future man and woman , of which I have kept no copy , will relate to future generations the cause of the failure of this experiment , if it ever does fail , as I trust in God it never will . " 
