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.

At the top of Indiana's journal page for April 8, 1959, is a sketch of "Twenty-First State" (later retitled Twenty-One Golden Orbs). The artist records that the work "was turned vertical today for its initial completion, and its significance was at once obvious: there is very much an elegant dignity to its upward rise. The off-center stripe—a chance enhancement of 27—was defined and it occurred to me that it was very much like a gate—perhaps I might call it 'Bosphoros' or 'Porte d'Or.'”

He then notes that his enthusiasm for this first panel led him to begin a second one. Indiana includes a sketch of the second work, Two Golden Orbs, along with its medium, oil on wood, and measurements, 84 5/8 by 43 3/4 inches. He then goes on to proclaim that there must be a whole series of spheres on panels. 

Indiana also records helping Ellsworth Kelly move three tables so that he could paint his floor, and receiving two books from from Dick (artist Richard Smith), who came over to have dinner. A note at the bottom of the page indicates that the day's entry was continued on the journal page for March 17, 1959.