Naturalization processes and requirements have changed a number of times, for researchers this means we find ourselves trying to discover the rules that were in affect when our ancestors lived.
Would you give up your citizenship for love?? There was a time when a lady would lose her American citizenship if she married an "Alien".
This is a snippet of the 1920 U.S. Census, happens it is for Black Hawk County, Iowa, but that really does not matter. (Hint, if you click on the graphic it will open to a larger view.)

This is Eula Lashbrook Jensen and her second husband Carl Jensen. Carl came to the US in 1904, as you can see from column 13. He has filed his papers for Naturalization as you can see from column 14. But, look carefully at column 14 again, and you will see Eula is shown to be an "Alien".
Eula became an Alien, when she married Carl, even though she was born in Iowa, and her father was born in Wisconsin. Eula's grandparents were born in England and in New York. So, by my count she was a second generation natural born citizen (via her paternal lines), but she was an alien in 1920.
By paying attention to those small little boxes on the census reports we may discover really interesting historical lessons and a few oddities as well.
The search continues of course, so far this is all I have discovered about Carl's attempt to become an American citizen:
According to "Black Hawk County, Iowa Petition for Naturalization Book 1", compiled by Black Hawk County Genealogical Society, 1988, we find:
Jensen: Carl Christian
Dist. Ct. B.H. Co. Ia Occupation: Farmer & Road Superintendent. b. 3 Apr 1884, Tollose, Den. Emigrated: ca 11 Oct. 1902 from Liverpool Eng. to New York on vessel Locania arr. 18 Oct. 1922 (??) Intention 5 Mar 1910 Waterloo, Ia. Not married. Denied. Dated: 18 Dec. 1915 B.H. Co., Ia. Nat. # 206.
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