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.

In his journal page for April 10, 1961, Indiana discusses altering an early construction, Womb. The page includes two sketches, sketch A illustrating an earlier stage of the work, and sketch B illustrating the changes he made that day. Indiana notes that he added a word (WOMB) to the sculpture, and that he removed the four front wheels and added two to the sides. He also records that he filled the wheel holes with studs, and that they "become like teats, almost displaced fr[om] 'breasts' above."

He also records that "The Battery is green buds on every bush."