Change of Surname - Hoogendoorn to Hidore

[Nookie]

Ponsio Hoogendoorn and his family came to the United States in 1878.  His wife was Cornelia Wyngaarten, and his children were Theodore, Ponsio, Hendrik, Wouters and Johan. By 1885 I see that they had changed their surname to Hidore, and the children now went under the names of Dores, Ponsio, Henry, Walter and John! They lived in Iowa at the time.

I would like documentation showing the change of surname. Can anyone please help or tell me where I could look for this?

Many thanks

[shellyesq]

I wouldn't assume the name change was definitely legally done, but you may find indication of a legal change in newspapers or naturalization records. 

[Nookie]

Thanks for your response. Unfortunately I can find no naturalization records for Iowa. Would they possibly have been done at a central government department between 1878 and 1885?