Ignatius L. Donnelly

Ignatius Loyola Donnelly (November 3, 1831 – January 1, 1901) was an American U.S. representative, populist writer, and pseudoscientist. He is known primarily now for his fringe theories concerning Atlantis, Catastrophism (especially the idea of an ancient impact event affecting ancient civilizations), and Shakespearean authorship. These works are widely regarded as examples of pseudoscience and pseudohistory.