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.

Indiana's journal entry for April 4, 1959, includes a sketch of Twenty-First State (later retitled Twenty-One Golden Orbs), a 48 x 95 3/4-inch oil on wood painting. He records that this is what he had been wanting to turn to for some time:

"it coming essentially from the twelve orbs, or apostles, from my largest work, but stymied when I saw Agnes' [Martin] new direction into circles. It comes from "ΣΤΑΒΡΟΣΗΣ" [Stavrosis, the Greek word for crucifixion], & I think very really, in rearthink, from seeing Newman’s show [Barnett Newman: A Selection 1946–1952, French & Company, New York, March 11–April 5, 1959]. It now seems all the more clear the direction I must take. The natural line down the length of the board I intend to use to set up a tension, not yet seen in my work."