Meyer Instruments has a detailed history of Leica published on their website:
Key Dates
1849: Carl Kellner founds an Optical Institute in Germany.
1869: Ernst Leitz becomes sole proprietor of the Optical Institute.
1892: A sales office is opened in New York City.
1920: Ernst Leitz II takes over the business, which is transformed into a public limited corporation.
1924: Ernst Leitz II decides to mass produce the Leica camera.
1951: Canadian operations commence.
1971: A production facility for stereo microscopes is established in Singapore.
1972: Wild Heerbrugg buys 25 percent of Leitz.
1986: Ernst Leitz Wetzlar GmbH and Wild Heerbrugg AG merge to form Wild Leitz AG.
1990: Wild Leitz Holding AG merges with The Cambridge Instrument Company; Wild Leitz AG becomes Leica Heerbrugg AG.
1992: Management buyout of the Leica camera business.
1997: Leica group is split into Leica Microsystems and Leica Geosystems.
History of Leica related posts:
History of Leica (video) and “20 fascinating facts you didn’t know about the camera maker”