Very successful as a stage magician, Alexander became more world-famous for his "psychic" abilities.
Though he did perform some conventional magic in his act, his reputation-maker was a segment in which he answered questions "mentally sent" to him by audience members.
His real fortune was made by doing private readings for large fees; the IRS claimed that after he retired (for the first time) in the early 1920's, he owed them over $3 million in back taxes.
Alexander also wrote The Life and Mysteries of the Celebrated Dr. Q, about the world of mentalism, and was rumored to be the money behind Floyd Thayer's magic manufacturing venture.
On retiring for the second time in 1943, he sold his entire act to mentalist Robert Nelson, including all remaining publicity materials. So much stock remained that at least two magicians were able to subsequently perform as "Alexander".
The powerful images on his posters make them highly collectible today. The red "The Man Who Knows" poster is frequently used by TV and movie set designers to create room sets with a magical mood.
Credit: This biography originated on MagicTricks.com. Please credit this source if you use this information.