Robert Indiana kept a series of illustrated journals during the late 1950s and 1960s, in which he discusses the development of his work as well as his daily life on Coenties Slip.

In his journal entry for September 5, 1962, Indiana writes that he turned to The Black Diamond American Dream #2, and "put it under [the] brush." He includes sketches of the "Jack" (left) and "Juke" (right) circles, and notes:

Some of its blackness turns into color today. The left [circle] becoming a green (permanent green light) and [the] right changing [to] cerulean blue, mixed with white.

Indiana then records that Campbell Wylly (a curator at MoMA) stopped by, and reacted "warmly" to the changes in The Black Diamond American Dream #2, He notes that Wylly might have been swayed to take "Loftiest Trucks" (Melville) for the Singer Building (an early New York skyscraper, razed between 1967 and 1969 to make way for One Liberty Plaza)  

Indiana also mentions calls from the art critic Gene Swenson, gallerist Allan Stone, and artists Harold Stevenson and Stephen Durkee.