"Delaware Crossing" is from a series of six prints included in the "Benjamin Moore Series" which were based on six paintings he did in 1961, also called the "Benjamin Moore Series". This lithographic series is one of only two series that the artist drew on lithographic stones, his other lithos were done on plates.
Axsom states in the catalogue raisonné, page 82: "Although the individual titles of this series refer to American Civil War Battles, the series name itself is the name of the commercial paint used for the paintings. Each painting was executed in a single unmixed Benjamin Moore color.
Although the selection of the six colors as a group - the three primaries and their secondaries - may have been deliberate, Stella has stated that the choice of any one color for any particular design was arbitrary.
To demonstrate the incidental relationship between color and design, the artist made foot square paintings of each configuration in which all six colors were used. This conceptualization was restated in the prints by printing the color trial proofs of each configuration in all six colors of the series. The conceit of pure colors was repeated in the print series by the use of unblended inks directly from the can."