Whoops! sorry. I did not read your post and thus go to the link provided on your post #47. This stating that Chester Arthur burned his private papers prior to death.
I know that in 1850 citizenship papers were drawn up for persons becoming American citizens to and stated clearly to this effect. That the applicant forswore allegiance to a foreign monarch. The ones I saw named the King of Belgium. Another one named Queen Victoria as another foreign monarch. (Certificate of citizenship for J.J. Dolan, of Lincoln, NM. Formerly of Ireland. circa 1883.
No dual citizenship then existed.