Although, according to Jo Hopper's notation in the record book, The "Martha McKeen" of Wellfleet represents a late August morning off Cape Cod and Hopper began this painting on 10 August, he did not complete the canvas until after he returned to New York in December 1944. Jo also recorded a subtitle, "Where Gulls Fill Their Gullets." When Hopper was asked about the title of this painting by the publisher of a small monograph of his work, he responded emphatically: "I should like to retain the title 'The Martha McKeen of Wellfleet' if possible. The young lady that the picture is named after has taken us sailing in Wellfleet harbor so often that the title has a sentimental value for us and Martha McKeen also. The title was given purposely to please her and I think it would make her feel badly if it were to be changed. There is no vessel with this name as far as I know. It was named after our friend."
Hopper was inspired to paint this and some of his other sailing pictures by sailing with Martha and Reggie McKeen of Wellfleet, a much younger couple. He had been forced to give up sailing on his own by Jo who thought it was too dangerous. While the canvas was in progress, the Hoppers also went to Provincetown so that he could study the gulls at a fish house on the railroad wharf. Jo felt that the man depicted at the tiller might be Hopper himself.
Ever since he built a catboat as a teenager, Hopper adored sailing. His love of solitude must have enhanced his enjoyment of sailing. He sketched numerous sailing boats as a boy in his hometown, Nyack, New York, a Hudson River port that had a shipbuilding industry during that time. The first painting he ever sold was Sailing the only work he exhibited in the famous New York Armory Show of 1913.
Although sailing boats appear in the oils he painted in Gloucester, the next action pictures occur in watercolour: The Dory, 1929 and Yawl Riding a Swell, 1935. The "Martha McKeen" of Wellfleet follows three other canvases of sailing scenes: The Long Leg, 1935; Ground Swell, 1939 and The Lee Shore, 1941. Each of these paintings utilises a horizontal strip of sky and sea, and sometimes land, parallel to the picture plane. Hopper's only preparatory sketch for The "Martha McKeen" of Wellfleet reveals that he originally considered placing a standing figure near the mast rather than the two seated men seen in the final painting.
His resolution is an impressive canvas with strong blue tonalities played off against the white sails and sand bar. Sunlight dramatises the entire composition and the gulls cast blue shadows. The action appears rather frozen in time but Hopper effectively captured the great strength of the sea and man's momentary harmony with it.