Brown is known for his pictures of hunting and military scenes, and his studies of horses and dogs. He painted a number of pictures from the American Revolutionary War, the Seven Years' War, and the Franco-Prussian War of 1870. His presentation is often anecdotal and humorous, his work characterized by refinement and charm. The Luxembourg possesses his "Before the Start," the Gallery of Dublin, "The Mountebank." He was also an etcher and watercolorist.