Noted for his extraordinary ability to capture the ambiance and feel of harbor activity, Mulhaupt became known as the "Dean of the Cape Ann School," despite his roots in the Midwest. The artist was particularly acclaimed for busy maritime scenes like the one in Boats at Gloucester Harbor, which won him wide patronage and critical acclaim. A fellow Cape Ann painter, Emile Gruppé, aptly characterized Mulhaupt's special empathy for Gloucester when he wrote:

There were painters in Gloucester in the old days who were more exact than he was -- more "authentic" in that they got the shape of each boat exactly right. But many of these painters, as you looked at their work, might just as well have been painting a scene in England or Norway. Mulhaupt got the smell of Gloucester on canvas. He captured the mood of the place -- and that's worth all the good drawing of a hundred lesser painters. [Emile Gruppé, Gruppé on Painting: Direct Techniques in Oil (New York: Watson-Guptill Publications, 1976), p. 89.]

In Gloucester Harbor, Mulhaupt evokes the feel of a clear, calm day on the town's busy commercial docks in a composition dominated by the cool blue-grey of the sky and its reflection in the mauve-toned water. The strong verticals of the docked boats' masts convey the scale of the harbor's maritime operations, while also establishing a dynamic abstract patterning heightened by the wharves' long wooden planks and grid-like railings. Here, Mulhaupt uses the soft forms of the ships' sails to counterbalance the picture's geometric component; they also suggest the day's calm weather conditions as they hang nearly motionless in the light wind. Though Mulhaupt painted a number of winter scenes that illustrate his ability to work with a limited palette, the present work, with its pleasing combinations of blue grays, mauves, warm red-oranges and greens, exemplifies his mastery of a wider range of hues.

Given Mulhaupt's well-documented working style and this picture's large size, it seems almost certain the artist created Boats at Gloucester Harbor for a major exhibition. Particularly during the 1920s, he exhibited wharf-themed works at the National Academy of Design in a series of submissions that won him prizes as well as a prestigious invitation to membership in that organization. Artist Charles Movalli observed that Mulhaupt's large exhibition works were never painted on the spot, but "were the result of considerable studio thought." He painted numerous 8 x 10 panels outdoors, bringing these sketches (which, according to Movalli, "were the envy of every painter in town") back to his studio, and then hung them on the wall where they served as references in creating major works like Boats at Gloucester Harbor ["Frederick Mulhaupt: New England Classic," American Artist (January 1977), p. 100]. The resulting paintings combined meticulous draftsmanship with an enthusiastic spontaneity, what writer Kristian Davies calls a "carefully executed improvisation" [Artists of Cape Ann: A 150 Year Tradition (Rockport, MA: Twin Light Publishers, 2001), p. 67].

Famous for his work ethic, Mulhaupt was apparently a rather quiet man who left a strong legacy in Gloucester. After growing up in Kansas, he studied at the Art Institute of Chicago, where he became an instructor. Like other artists of his day, he traveled to Paris for further study, also venturing to St. Ives, England, perhaps the source of his aptitude and enthusiasm for harbor scenes. By 1904, in order to work in the mainstream of the art world Mulhaupt made his way to New York where he joined the Salmagundi Club, an artists' association where he exhibited regularly. He first visited Cape Ann in about 1907, spent many summers there, and moved there permanently in 1922. His second Cape Ann studio, purchased in 1932, was a former blacksmith's shop in Rocky Neck that sat on pilings in the harbor. This setting provided a unique vantage point, apparently so compelling to the artist that he painted there year round despite the lack of running water during the winter months [Movalli, p. 101].

Mulhaupt devoted a large part of his later career to mural commissions, creating works for the dome of the Kansas State Capitol building; the Coney Island Cyclorama; the World's Fair at Buffalo, New York; the Stalter Theatre in Cleveland; and perhaps best known, a mural depicting Gloucester's shipbuilding activity for the town's Maplewood School. When that school closed in 1982, the mural was moved to the O'Maley School, suggesting the high regard with which it is held in the local community [Kathleen Kienholz, Frederick J. Mulhaupt: Dean of the Cape Ann School (Gloucester: North Shore Arts Association, 1999)].

Mulhaupt's works are in a number of prestigious public and private collections, including the National Academy of Design, New York; the Fogg Art Museum, Harvard University, Cambridge, Massachusetts; the Reading Public Museum, Reading, Pennsylvania; the Cummer Museum of Art, Jacksonville, Florida; the Indianapolis Museum of Art, Indiana; and the University of Michigan Museum of Art, Ann Arbor, Michigan, among others.