Well. Wikipedia:
Wilbur B. Foshay was an American businessman, who built a fortune buying utilities throughout the Midwest in the early 20th century. Foshay had built up three different utility company empires; selling each one in turn to fund the acquisition phase of the next. His second empire included three utility companies that served the Crookston, Bemidji, and Hallock areas in northern Minnesota. As he worked on his third and largest utility empire, Foshay built the Foshay Tower in Minneapolis, Minnesota, which opened in August 1929.
In 1932 he was convicted of conducting a "pyramid scheme" with shares of his own stock. He was sentenced to 15 years in prison. President Franklin Roosevelt commuted 10 years from Foshay's sentence, but Foshay only actually served three years in Leavenworth because of "good behavior." President Harry Truman granted Foshay a full and unconditional pardon in 1947.