ALEXANDER (June 30, 1880–August 5, 1954), whose full name was Claude Alexander Conlin, was born in Alexandria, South Dakota, United States.
Between 1915 and 1924, Conlin, under the stage name Alexander, The Man Who Knows, was a popular and highly paid stage mentalist. Alexander promoted his psychic act as a form of mental telepathy or mind reading. Audience members gave him sealed questions, which he answered from the stage. His techniques were not revealed during his lifetime. He is credited as the inventor and/or popular developer of a number of electrical stage effects which were the forerunners of modern electronic stage effects. Sources state that he earned multiple millions of dollars during his career on stage and that during his lifetime he may have been the highest paid entertainer in the field of magic.