Part 1: Where was Frank Stoutenberg born? Iowa or New York

Some time ago I was contacted by a distant cousin to see if I knew something about Frank Stoutenburg, son of James and Susan Stoutenburg. She had conflicting information concerning his place of birth. She knew that his parents were born in New York as were all of his siblings, all of whom were younger than he. She had been told that Frank was born in Durant, Iowa. Frank's brother John was born 2 years after Frank in Sullivan County, NY. She was wondering if someone had made a mistake.

As it happened, I had Frank Stoutenberg's death certificate. The informant is a B. Murphy of Ancker Hospital who appears to be an employee of the hospital. Therefore, the information is sketchy. The death certificate says that he lived in St. Paul for 40 years and was born in 1860 in New York. Frank seems to believe that he was born in New York because in the 1870 and 1900-1920 US censuses and in the 1905 Minnesota census his birthplace is listed as New York.

I decided to see if I could find a Frank Stoutenburg and/or his parents in the 1860 census. Given the clue that he may have been born in Durant, Iowa, I found Frank Stoutenberg and his parents living in Wilton Township, Muscatine County, Iowa. According to Wikipedia, Durant spans three counties, Muscatine, Cedar and Scott. However, Plat Maps of Iowa as late as 1930 show Durant in Cedar County.

Wilton Township was organized in 1853 and the town of Wilton was platted in September 1854. A competing town was established in neighboring Cedar County in Farmington Township. This was the town of Durant. Based on the 1860 Census, Frank and his parents were living in Wilton Township and the nearest post office was Durant in Cedar County. This suggests that the farm on which the family resided was nearer to Durant than to Wilton. Frank was most likely born on the farm in Wilton Township in Muscatine County. Mail sent to James and Susan Stoutenberg would have been addressed to the Durant Post Office in Cedar County.

So the mystery of where Frank Stoutenberg was born is solved, but another remains. Why did James and Susan move to Muscatine County, Iowa? Then, why did they return to New York sometime between July 10, 1860 (when the family was enumerated in Iowa) and January 21, 1861 (when their second son was born)?