Bio posted at rootsweb.com: http://www.rootsweb.com/~iaallama/Bios13/barthell_m.htm
Bio of brother and business partner: http://www.rootsweb.com/~iaallama/Bios13/barthell_c.htm
Michael J. Barthell appears in the 1910 Iowa Census, Allamakee County, Makee Township, Age 39, father born in Germany, (can't make out where mother was born, "Can. English"?), Occupation Real Estate.
Wife Jessie, Age 29, born in Iowa, father born in New York, mother born in West Virginia