Ignatius Loyola Donnelly (November 3, 1831--January 1, 1901) was a U.S. Congressman, populist writer and amateur scientist, known primarily now for his theories concerning Atlantis, Catastrophism (especially the idea of an ancient impact event affecting ancient civilizations), and Shakespearean authorship, which many modern historians consider to be pseudoscience and pseudohistory. Brother to Eleanor C. Donnelly, Donnelly's work corresponds to the writings of late 19th and early 20th century figures such as Helena Blavatsky, Rudolf Steiner, and James Churchward and has more recently influenced writer Graham Hancock. The concept of Atlantis as an antediluvian civilization became the inspiration for the 1969 pop song hit Atlantis by Donovan and the 2009 film 2012 by Roland Emmerich.
