Lifelong horse enthusiast, philanthropist and Thoroughbred owner/breeder Phyllis Mills Wyeth died Monday at the age of 78, according to a statement released by the Brandywine Conservancy and Museum of Art, of which Wyeth was a long-time supporter. Wyeth, who achieved her greatest success in racing as the owner/breeder of 2012 GI Belmont S. hero Union Rags (Dixie Union), passed away with her husband, acclaimed painter Jamie Wyeth, by her side. Born in New York City to the late James and Alice du Pont Mills and raised near her family's Hickory...