The following data is extracted from History of the Pacific Northwest, Oregon and Washington, 1889.
GUSTAVE ROSENTHAL. - This well-known merchant was born in Bavaria on the 4th of July, 1840. He continued to live in his native country until 1856. In that year he emigrated to America. The first three years of his stay he spent in Boston. Then, removing to the city of New York, he was engaged in mercantile business until 1861. In September of that year he came by the Panama route to California; and two years later he resumed his journeyings, coming to a final pause at Olympia, Washington Territory. There he soon embarked in the business of general merchandising in partnership with Isaac Lightner. In 1874 Mr. Rosenthal purchased the interest of his partner, and has since conducted the business independently, being now one of the oldest business men in Olympia.
In 1869 the office of county treasurer was conferred on Mr. Rosenthal. The wife of Mr. Rosenthal was Miss Katie Bettman, to whom he was united at Olympia, and by whom he now has an interesting family of four children, Bertha, Samuel, Caroline and Fannie.
Source: History of the Pacific Northwest, Oregon and Washington, 1889