A sketch of Comma, originally titled Homage to José, appears in Indiana's journal entry for December 12, 1959. The work, painted in gesso on a wooden plank, is an homage to the Fillipino poet José García Villa, who was a friend of the artist. García Villa was known as the "Comma Poet" for his signature style, where commas are placed after every word to regulate rhythm, density, and tempo.
Indiana would return to literary themes in later, more complex works, which he referred to as "literary paintings." These include a series of 1961 paintings incorporating quotes from the nineteenth-century American authors Henry Wadsworth Longfellow, Walt Whitman, and Herman Melville, and a 1964 Brooklyn Bridge series incorporating lines from Hart Crane's 1930 poem "To Brooklyn Bridge."
Comma was originally in the collection of gallerist Martha Jackson. Jackson had included his herm French Atomic Bomb in the landmark exhibition New Media—New Forms I. The exhibition, held at the Martha Jackson Gallery, was the first major showcase of current assemblage works, and the first time Indiana's work was exhibited in New York City.