The Baldwin Memorial Stairway, located between University Avenue and Delta Phi fraternity (Llenroc, the house built by Ezra Cornell), was a gift to Cornell University, to Delta Phi, and to the citizens of Ithaca from Arthur J. Baldwin (Class of 1892) in memory of his son, Morgan Smiley Baldwin (Class of 1915). Constructed in 1925, the cornerstone for the Baldwin Memorial Stairway was laid on November 11, 1925 by Donald R. Baldwin (Class of 1916), Morgan's brother. The box was placed in the stone by George S. Tarbell, president of Delta Phi, during a ceremony which included a speech by Cornell President Livingston Farrand. During repairs to the Stairway in 2006, staff from the Cornell Masons Shop encountered the copper cornerstone box. It was reopened on September 26, 2006 during repairs to the structure. A new cornerstone box was dedicated on November 11, 2006.

Morgan Smiley Baldwin of East Orange, New Jersey, graduated from Cornell in 1915 with a Bachelor of Arts degree, and received a law degree from Columbia University. At Cornell, he was a member of Delta Phi. When the United States declared war against Germany, he enlisted in the 7th New York Regiment, which became the 107th Infantry, and a part of the Twenty-seventh Division. Baldwin trained at Camp Wadsworth before being sent to France in May 1918. Towards the end of September, his unit took up position with the British Fourth Army in preparation for the attack on the German Hindenburg line. After several days of fighting, he was severely wounded on September 29. Baldwin died of his wounds on October 9 at the British General Hospital 12. He was buried in Saint Sever Cemetery outside the city of Rouen.