Occult World Disclosed at Theosophist Meeting, 1902
Apparently Chicago was a popular place to hold national Theosophist conventions. A few years later, Theosophists would meet at Stevens Hotel. In 1902 they met at Steinway Hall, which was located at 64 East Van Buren street from 1896-1970.
Chicago Daily Tribune, September 29 1902
I love how these things start tying together. This is the same address that at least one of the offshoot groups of C.F. Russell's Choronzon Club met at from the 1940s through the 1960s.