He is sometimes called William MacTaggart the Younger to distinguish him from his grandfather, the painter William McTaggart.
William Shakespeare | William Laud | William Blake | William | William III of England | William Morris | William McKinley | William Howard Taft | William Ewart Gladstone | William the Conqueror | William S. Burroughs | William Shatner | William Faulkner | William Randolph Hearst | William Wordsworth | William Tecumseh Sherman | William Hogarth | Prince William, Duke of Cambridge | William Penn | William Jennings Bryan | William Gibson | William Wilberforce | William James | William Makepeace Thackeray | Fort William | William Hanna | William Hague | William III | William Hurt | William Walton |
Simpson supported artistic talent and befriended painters such as William MacTaggart, George Paul Chalmers, W. Q. Orchardson, Sam Bough, James Cassie and Alexander Fraser.