According to the Internet source given below, John Milton Delcamp was an American pianist born in Norristown, Pennsylvania. After studying at Coombes Conservatory in Philadelphia he made his career as a silent film accompanist as well as making piano rolls for Republic Roll Co. and the Ampico Roll Company. Of ragtime interest is his Rackety Rag
(1920) which was neither published or copyrighted existing only as a piano roll.
Further sheet music at DBE: ON HOLD