Ewald Alfred Arthur Frederick William von Cotzhausen (July 21, 1838 – December 10, 1924) was a German American immigrant, lawyer, and politician.

[1] In 1870 he was hired as general counsel for a proposed rail line, which eventually became incorporated into the Chicago and North Western company.

[4] He was elected during a rare moment when the Democratic Party held power in state government, but he voted against the signature law of that session, the railroad regulation bill.

His most noteworthy contribution from his term in office was a softening of the Graham Liquor Law, which had outraged Wisconsin's German population.

But Cotzhausen broke with the Democratic Party over the 1896 nomination of populist William Jennings Bryan, and became a progressive Republican in his later years, endorsing and campaigning for Robert M. La Follette.

[3] He was also one of the founders and key organizers of the Milwaukee Municipal League, which encouraged progressive reform in cities around the state and contributed to the growth of La Follette's movement.

[9] The mansion he occupied for the last fifty years of his life (then in Greenfield, now within the city limits of West Allis, Wisconsin) is still largely intact at 2855 S. Waukesha Road.