Several reports of the AAUP’s founding mention that it took place in the Chemists’ Club in New York.
While there is a website by the current Chemists’ Club, it moved its location and sold the building in which the founding took place.
I was able to locate information about the original location of the Chemists’ Club, which is 50-52 East 41st Street, down the street from both Penn Station and the New York Public Library. It turns out to be a hotel now, and when I conducted research on the AAUP’s history in the Columbia University Archives over Spring Break, we stayed there.
It’s worth a visit, particularly the restaurant, which is the only room large enough to have held that many people. The minutes of the meeting thank the Chemists’ Club and also “the Women’s University Club for hospitalities to women members of the profession in attendance at the meeting.”
Given how very male-dominated the profession was in 1915, it would be interesting to determine how many female professors were in attendance. There were around 250 attendees total, and several invitees who didn’t attend joined those present as charter members. The Association published a list of charter members who were invited to attend the organizational meeting and who joined during the first few months of 1915.