From the Book of Dow, page 660: Joseph W Dow, banker in Illinois, later Plymouth,Wis; m. Nov 23,1837 Alice B Champney b.Charlestown,Mass,Jan 15,1815. Children: Sarah E Josephine T Susie B Alice Edward A b.Apr 1,1853
This Edward, pres. of State Bank,Plymouth; m. Dec 25,1876, Ida J Hotchkiss b.Plymouth Oct 5,1855. Ch: Edith Alice Florence Robert W b.Sept 25,1881; in 1922,broker of Milwaukee Edward H.
With Robert age 38 in 1920 Plymouth census (with his wife Clara), this puts his birth at ca.1881-2 in WI with parents born IL and WI. This would be the family you are looking for.