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 January 29, 1959, and January 29, 1960. The entry for January 29, 1959, includes a sketch of Sixth State, a 32 ¼ by 24-inch painting that Indiana began that day. He notes that the work is wood grain on wood grain, rubbed with white. Indiana also records seeing a barge tied up, named Traprock, which stuck him "as a v[ery] fine name for a painting," and going to the ballet at the City Center. 

The entry for January 29, 1960, includes a sketch of a construction (later titled Four). Indiana details his work on the "long wooden panel," noting that he added three geometric patterns to the gesso circles, and that "heightening the interest of these gesso discs, rubbed pale, has been my concern for some time now."  He also mentions actress Delphine Seyrig coming over for a fitting (with his partner, fashion designer John Kloss), and that he caught The Informer on television, "the classic I've missed these many years."