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 13, 1959, and January 13, 1960. In his entry for January 13, 1959, Indiana records that it was not a productive but a pleasant Tuesday morning of seeing friends and studios on the Slip. He notes having three breakfasts, one alone, one with Ellsworth Kelly, and one with Agnes Martin and Ann Wilson. He also mentions that he received a call asking him to work a third day at the Cathedral of St. John the Divine, which he could not do as it would keep him from getting any work done. He asked Charles Hinman if he would like to take it over, which Hinman said he would.

The entry for January 13, 1960, consists of a sketch of Porcupine, a metal on wood sculpture with gesso surfaces, measuring 10 x 14 inches.