While Dean is primarily known for marine paintings from the Boston region, he also created a wide-range of art from his travels to France, the Netherlands, Italy, Belgium, England, Canada and Puerto Rico.

His youngest brother, Josiah Stevens Dean married May Lillian Smith in 1888 and became a prominent Boston lawyer and judge who died in 1941.

[8] In 1885, after his return from Europe, Dean fitted up a yacht of twenty-six tons, and set out on a four-month sketching cruise along the New England coast, visiting every port between Boston and Eastport, acting as his own skipper and pilot.

Shortly before his death, which occurred in 1912, he spent an entire summer nominally as ship's carpenter (since law would not permit his going as a passenger) aboard one of the whalers out of Bedford.

During this voyage, which was confined to the North Atlantic ground off Cape Hatteras, he made valuable sketches and studies of present-day whaling operations.

After graduating from public school, Dean left Boston to learn all details of the cotton manufacturing business at a mill in Tilton, New Hampshire.

[8] After trying ranch life for one month in Texas,[11] in 1881 Dean returned to Boston, where he studied painting under the direction of Achille Oudinot,[12] a pupil of Jean-Baptiste-Camille Corot and Charles-François Daubigny.

[13] This master awakened a deeper insight into the soul of things, and helped him to get a better idea of composition, atmosphere, perspective, light and shade.

[10] After earning $2,500 from the sale of his paintings,[10] in 1882, at the age of 28, Dean traveled to France, where he first spent seven months on the French coast, sketching the local people and boats in Brittany.

[3] In England, he secured an old chapel as a studio in the village of Cornwall, and finished a number commissions for "Manchester gentleman" of Mediterranean scenes.

[10] Perhaps Dean's most important work, Peace (see image) is a large painting (9 × 6.25 ft or 274 × 191 cm) depicting the original US Navy fleet at rest in Boston Harbor.

When the North Atlantic squadron came into Boston Harbor a few years ago, Mr. Dean anchored his yacht alongside the white war ships, and secured studies for his painting.The US House Resolution 5454 in 1900, which proposed to purchase "Peace" for $15,000, states the following: The bill proposes to purchase an historical painting entitled "Peace" by Walter L. Dean of Boston, Massachusetts.

"Peace" shows them as originally constructed, and is a means of keeping in view the type of ship which started the Navy of which every American is justly proud.

There is no question among the minds of your committee but what it is perfectly proper that this historical painting should be owned by the Government and hung in a suitable place in the Capitol building.

It was shown at the Columbian Exposition in Chicago in 1892 [1893], where it occupied a place of honor in the United States section of the fine arts department.

There is perhaps no painting of recent years which has been more favorably received and commented upon wherever seen by artists, art critics, naval officers, and the public generally than "Peace."

The painting remained with the committee throughout various relocations in the Capitol and, in 1919, to the Cannon House Office Building; Peace has been on view in room 311.