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.

This journal page covers September 14–16, 1960. In his entry for September 14 Indiana writes that he took about eight photographs of his constructions and loft to Broad Street to be enlarged. He explains that he wanted to get them to the gallery for Mrs. (Martha) Jackson to see (Indiana was being included in the New Media—New Forms II show, from September 28–October 22, at the Martha Jackson Gallery).

On September 15, Indiana records that the first event of the day was a call from Jackson's secretary to arrange a visit to his studio, and that this "was a great trigger [to] action." The entry includes a sketch of an unnamed construction (later titled U-2), 45 3/4 by 12 3/2 inches, with a note indicating the addition of an incised star. 

Indiana's September 16 entry includes a sketch of another unnamed construction (later titled Zig), to which he added black and yellow stripes to the front and sides. Indiana explains that he cancelled his plans to go to Fire Island, as it would "be really unthinkable for me to proceed [and] spend 2 or 3 of these few days before Mrs. J. [Jackson] comes in [the sun] on Fire Island."