Sidney Janis, director of the Organising Committee of the exhibition Picasso's Guernica, for the Spanish Refugee Relief Campaign, thanks the senator and his wife for their donation and informs them of the change of date for the opening of the exhibition at the Valentine Gallery.
Reference in the source Archive:
Spanish Refugee Relief Association Record, 1935-1957, Part D: Affairs, Box 11, Picasso Exhibit n. 1
Sidney Janis's letter to Simon Guggenheim