Before retiring to Harford County, Maryland to raise horses, Flannery had a successful career in the field of advertising in New York. His interest in painting, which paralleled his love of horses and the turf, was instilled early in life at his childhood Kentucky home by his mother, an amateur artist. While Flannery is remembered as a portraitist of horses in the tradition of British artists, Benjamin Marshall (1767 – 1835) and John Frederick Herring Sr. (1795 – 1865), he also produced vivid images of racetracks, breeding farms and the activities associated with the world of racing. Of these two passions in his life, Flannery once commented: “It is my observation that a painter always enjoys a conflict between logic and his instincts, and with me instinct always wins. It is much the same in breeding horses. There can be no doubt that the logic of the geneticists is the soundest foundation on which to proceed, but in the end your instinct tells you when you have a really good horse.”