IOWA
Friedrich Julius Mittelstadt (1827-1890) moved from Prussia to Wisconsin in 1857 and to Iowa in 1860. He fought in the Civil War on the Union side and after that became an Indian fighter with the US Cavalry in South Dakota.
The next generation all lived in Iowa where one (see above chart) changed his name to "Mittelstedt" during World War I.
The above information was supplied by Richard David Mittelstedt and his son Richard Eugene both of Minneapolis.