/ The Secret Teachings of all Ages /
Knapp was born and raised in Newport, Kentucky in 1853. He studied at the McMicken School of Design in Cincinnati. He went on to hold various positions as a designer and lithographer at Russell Morgan Lithograph, Strobridge Lithograph, Cincinnati Process Engraving, and Standard Publishing where he illustrated books and magazines. It was while at Standard Publishing that Knapp met Curtis Gates Lloyd, youngest brother of John Uri Lloyd. John Uri Lloyd hired Knapp to illustrate his first novel Etidorhpa, published in 1895 – a partnership that would continue on to several other of Lloyd’s novels. In the early 1900s, Knapp was commissioned by Curtis Gates Lloyd – who became one of the leading authorities of early mycology research – to paint 40 watercolors of various fungi. These plates are on display at the Lloyd Museum. In 1918, Knapp moved to Los Angeles, California, where he continued working as a designer, illustrator and painter, at one time employed by Thomas Ince Studios where he participated in the very early days of the movie industry.
During this period he also became illustrator of many of the works of esoteric scholar Manly P. Hall, working with Hall on Initiates of the Flame, and later his magnum opus The Secret Teachings of All Ages. Knapp also designed a Tarot deck in collaboration with Hall.