Ignatius Loyola Donnelly (1831-1901), was an Irish-American born in Philadelphia, Pennsylvania. He studied law and was admitted to the bar in 1852. He moved to Minnesota in 1857. He was elected Lieutenant-Governor of Minnesota when it became a state in 1859, at the age of twenty-eight and was re-elected in 1861. He served as a Congressman from 1863 until 1869 and was a state 
senator from 1874 to 1878. The People’s Party, of which he was a founder, nominated him for Vice-President of the United States. He was a political liberal, being in favour of women’s suffrage and against slavery.
Donnelly was also a journalist and the author of a number of books. In 1882 he published his most famous work[021] on the subject of Atlantis, which is still in print today, although many of the more recent editions have been heavily edited to exclude some of Donnelly’s more outlandish ideas. Donnelly concluded that Atlantis was real and located in the Atlantic. He suggested “the gods and goddesses of the ancient Greeks, the Phoenicians, the Hindus, and the Scandinavians were simply the kings, queens, and heroes of Atlantis; and the acts attributed to them in mythology are a confused recollection of real historical events.” Similar ideas have been developed by Joseph Robert Jochmans.
Donnelly’s book contains a list of thirteen theses (See: Atlantis: The Antediluvian World), which he then proceeds to ‘prove’, drawing on Plato’s text and the scientific knowledge of this period, not to mention a generous helping of pure conjecture.
Many have followed his thinking since then and in 1886, Donnelly published a sequel, Ragnarok[022] to his work on Atlantis that dealt with the idea of a cometary impact with the earth. Although he was not the first to make such a suggestion, he was responsible for introducing Velikovskian style Catastrophism to a popular readership over half a century before Velikovsky.
Following the remarkable reception that his books received, Donnelly was elected to membership of the American Association for the Advancement of Science. However, it did not take long before critics emerged. One was John Francis Arundell also known as Lord Arundell of Wardour (1831-1906) who published his criticism in book form[648] in 1885 and can be read or downloaded online(c).
Donnelly also wrote a 1,000-page work[023] that attempted to prove that Shakespeare had not written all that he has been credited with. Obviously a man with time on his hands, he also published a number of works of fiction under the name of Edmund Boisgilbert MD.
There is a wealth of Internet material relating to Donnelly e.g. (a)(b).
(a) http://www.geometry.net/detail/book_author/donnelly_ignatius.html
(b) http://www.stanford.edu/~meehan/donnelly/index.html
(c) http://www.archive.org/stream/cu31924028993355#page/n7/mode/2up
