Orange, New Jersey, USA
A major manufacturer of high-specification mechanical calculators, it produced a few electronic desktop calculators in the late 1960s.
Frank Stephen Baldwin, 1838-1925, American inventor, began in 1870 to experiment with the design of mechanical calculators. The device was patented and marketed in 1875. The improved 1875 machine initiated the development of the second fundamental principle in rotary four-rules calculators which became known as "The Baldwin Principle." Baldwin developed many more calculators during his life. His last model was the forerunner of the Monroe machine. The Monroe Calculator was used extensively in the 1930's. The Monroe Calculator Company was formed in 1912 and was a pioneer in electric adding machines. In the 1970‘s most Monroe – a subsidary of Litton Inc. - calculators were OEM-products manufactured by Canon or Compucorp (Computer Design Corporation of Los Angeles, California ). Monroe Calculators are still sold today through Monroe Systems for Business.
Independent of W.T.Odhner (1874) in Europe, in the USA Frank S.Baldwin set up the "Pin-Wheel" mechanism in 1872 to build calculators. In 1911 F.S.Baldwin teamed with Jay R.Monroe to develop a "Split-Stepped-Drum" calculator with full-keyboard. They were easy to make and light-weight. This was the start of the MONROE Calculating Co. in New York, which moved later to Orange, New Jersey / USA. As a successful company they survived into the "Electronic Age". The Adding/Printing Calculator »MONROE« Mod.811-H14 in this collection was made by OLYMPIA Werke Wilhelmshaven / West-Germany. The same machine came to the European market with its »OLYMPIA« logo. It seems, that this calculator was one of the best on the market of that time: Nice looking, small, easy to change paper roll and ribbon, printing negative numbers and also "real" negative results in red. In the MONROE catalog of 1965 it is stated, that this machine has a "foreign origin"...
Source : beuth-hochschule.de