On September 15, 1938, Asimov wrote in his diary:
I received a postcar this morning from a Frederik Pohl, who informs me that Jack Rubsinson asked him to invite me to a meeting of the Futurians at 730 Nostrand, next Sunday at 2 pm. .. I have decided to consent and accept the invitation, after having consulted with Mama and received her OK, and immediately sent off a postcard to that effect. If the meeting turns out to be very interesting I'll join up.