In November 1940, Portinari received a letter from Archibald MacLeish, the director of the Congress Library in Washington:

"...Since long we have the wish to display in the entry to the Hispanic hall a mural painting by some great Latin American artist to emphasise more the objectives of the Hispanic Foundation and its great interest in the question of American modern art. Now I have the hope to raise funds for the long-awaited fresco. I am writing now to tell you that I am considering you for this important and difficult job. ..."