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.

His journal entry for February 15, 1962, includes a sketch of Law, a construction comprised of an iron and wood wheel mounted on an old beam. Incised and gessoed, it was then mounted on a base made from a beam removed from Jack Youngerman's old Coenties Slip loft. Indiana explains that he had changed the construction, begun in 1960 and formerly titled Roman Machine of Justice, in 1961 but left it "unfinish[e]d until today." He notes that the choice of words came quickly after all of this time, and records adding the word "Lex" ten times, in pencil washed over with a thin coat of gesso, and the letter "X" on the side spaces, as well as signing the work with the stencil "I" and dating it NY/VX.  

Indiana also mentions that Law was selected by Campbell Wylly to go in the next Penthouse show at the Museum of Modern Art, and that Wylly had called that day asking about his "column capitals," and to confirm that the piece (Law) might be picked up the following Tuesday.