The first large conference on electronic and electromechanical digital computers ever held took place in Cambridge, Massachusetts from January 7-10, 1947. About 250 people attended. Notably the computers were called "calculating machinery" at the time, reflecting the traditional association of the word computer with people rather than machines. Significantly the conference occurred when only one electronic digital computer, the ENIAC, and one major electromechanical machine, the Harvard Mark 1, were operational.
At the conference Samuel H. Caldwell suggested the formation of an organization of people engaged in this new field. This organization was later named the Eastern Association for Computing Machinery. It was the predecessor of the ACM (Association of Computing Machinery).
The proceedings of the conference were published as Proceedings of a Symposium on Large-Scale Digital Calculating Machinery. Jointly Sponsored by the Navy Department Bureau of Ordnance and Harvard University at the Computation Laboratory, 7-10 January, 1947. Cambridge, MA: Harvard University Press, 1948.