He bought the Waterhouse Electric Light Company in 1888 and the United States Illuminating Company in 1890, giving Westinghouse their own arc lighting systems as well as control over all the major incandescent lamp patents not controlled by Edison.
V roce 1888 koupil Waterhouse Electric Light Company a v roce 1890 United States Illuminating Company, čímž získal vlastní obloukové osvětlovací systémy a také kontrolu nad všemi hlavními žárovkovými patenty, které neovládal Edison.