German-born inventor who has been called a second Gutenberg because of his invention of the Linotype machine, the first device that could easily and quickly set complete lines of type for use in printing presses. This machine revolutionized the art of printing.
A precocious boy, Mergenthaler was anxious to study engineering, but his father, burdened with financing the higher education of older sons, found the expense beyond his means. He was apprenticed to a watchmaker at age 14 and attended technical school classes at night. In 1872 he emigrated to the United States, becoming a citizen in 1878. While employed in the Baltimore machine shop of a relative, he worked on plans for a device to make type molds of papier-mâché. This device proved impracticable, but Mergenthaler became dedicated to the problem involved—setting type by machine. In 1886 he produced his Linotype, which, by bringing copper matrices into brief contact with a molten but fast-cooling alloy, rapidly molded column widths of type. The machine reduced costs by speeding up the printing process; hence it fostered a dramatic expansion of all areas of publishing. Mergenthaler later patented other successful inventions, but developing the Linotype remained his life interest.
He died of tuberculosis on 28 October 1899, Baltimore.

Link to Wikipedia biography