In this series of three letters (housed in the archives of the Art Institute of Chicago), museum officials correspond with representatives of the Mexican Ambassador to the United States and the U.S. Department of State regarding the exhibition Posada, Printmaker to the Mexican People. In a letter dated March 10, 1944, Chauncey McCormick, president of the Art Institute of Chicago, invited Francisco Castillo Nájera, the Mexican ambassador to the United States, to the exhibition’s opening, which he called, “the first example of an interchange between the Mexican Ministry of Education and an American art museum." In another letter dated March 14, 1944, the director of Fine Arts at the museum invited Charles Thomson, chief of the Division of Cultural Relations at the U.S. Department of State, to the Posada opening, informing him of the invitation extended to the Mexican ambassador and of the Art Institute’s plans to send a selection of their Toulouse-Lautrec works to be shown at the Palacio de Bellas Artes in Mexico City during the summer of 1945. In the final letter, dated March 17, 1944, a minister of the Mexican ambassador accepted the Art Institute’s invitation on behalf of the ambassador.