After making a grand tour of Italy with a group of American students, Thompson made his way to Brittany. He intended to stay there for the summer, before returning to Paris. Concarneau became his base for the remainder of his stay.

Over the years the region attracted artists from around the world. Frances Hodgkins, Paul Gauguin and Claude Monet, to name a few. Rapid changes in city life resulting from modernisation, commercial and industrial expansion led to the creation in the last decades of the 19th century of a rural ideal, a life lived close to nature. To the artist, ports were not inanimate, but living places which appeared to absorb and express the personalities of the sailors and fishermen who made and used them.

In his work, Thompson evolved a technique which made a direct statement. He worked to identify colour with tone so that each supported the other. The subject of Horses on the Quay, Concarneau was a common sight at Concarneau. Horse's patiently waiting for the catch from the Tunny Boats at the Digue. Thompson sought personal expression and symbolic meaning creating an overall atmosphere of drama. Paint was loaded on to the canvas in a variety of directional strokes. The dark shapes of men and horses on the wharf are set against the hills which is reminiscent of his former tutor Petrus van der Velden.

Thompson, who died in 1973, is buried at the cemetery at Concarneau.