Four was first recorded by Indiana in a journal entry dated January 18, 1960, in which he describes his creative process and the development of the work, which he refers to as Stele of Four Orbs. The sculpture originally consisted of an "iron hoop" and three orbs painted with gesso which he wiped down so that the grain of the wood showed through. This technique was in keeping with the methods used earlier in his 1959 orb paintings and in other works on plywood. The work remained in this state until April 1962, when Indiana added the Gothic numeral "4" to the lower three circles and the word four to the bottom of the construction.
Although Indiana would later develop a personal theory of numbers, with each number representing a stage of life and with specific colors associated with it, the numbered herms are more literal. In Four, as well as the herms Two (1960–62) and Six (1960–62), the number references the number of orbs featured on the work. The number four is also notable as the U.S. postal code for Coenties Slip in the era before the adoption of the five-digit code. In 1960, Indiana's address would have been written as "31 Coenties Slip, NY, NY 4."