On the level: Empire Level Manufacturing Company, Milwaukee, Wisconsin

Popular Mechanics, February 1951

Henry Ziemann, a master carpenter, founded the Empire Level Manufacturing Corporation in 1919. In the following three years, he created the adjustable level with interchangeable and replaceable vials. The company went on to introduce the torpedo levelin 1935, the Mono vial, the magnetic level and top read levels.  In 1987 they acquired the Peerless Level Company (which made wood levels) and in 2010 the American Level Brand (mahogany levels).