Rudolph K Douglass - Is he known to anyone?

[William Douglas]

I received the following, which I have translated from French:

Comments: Hello,
I am contacting you, because, almost 200 years ago (July 16, 2021), Antoine Leclerc aka Milfort Tastanegy died on the property of friends in a small village in France, Villevallier (Yonne). He was born in Thin le Moutier (Ardennes-France).

In the meantime, this colorful character went to the USA for almost 20 years. He lived among the Creek Indians near Little Tennesse in Alabama, where he became the Great War Chief or Tastanegy.
He married Jeannet McGillivray and had children (including Polly, Alexander ..) Then he returned to France with the aim of keeping Louisiana for France, to no avail. Having become a general, he remarried, had a son, whose current descendants I have found!

With French descent, we are looking for American descent. A letter sent by a certain Rudolph K Douglass to the military archives in Vincennes (France) in 1938, informs that he is one of the descendants of this Tastanegy. He is looking for information about his ancestor. I just found his name on your site, but also, I just found the mention of a book he wrote on his ancestry:

I also found his dates of birth and death, as well as the photo of his grave in Baltimore, etc.
I will be very interested in getting the book written by Rudolph Douglas, to understand how he descends from Tastanegy, being born in France and immigrated to the USA in 1915, but also to have contacts with his descendants to discuss about their ancestor and let them know about French descent.

Rudolphe Alfred Alphonse Kretzinger Douglas  has an entry here: 
Rudolphe Alfred Alphonse Kretzinger Douglas b. 1896 d. 1988: Dougla...  I would welcome more on his French background - and on the content of his books, detailing his native American background.

[William Douglas]

https://fr.wikipedia.org/wiki/Jean-Antoine_Leclerc_de_Milfort

[Russell Lynn Drysdale]

https://jayur.files.wordpress.com/2009/01/a-study-of-sweat-lodges-i...

[Russell Lynn Drysdale]

Google ''Great War Chief or Tastanegy'' there are oodles of references to Milford  . From what little I have read  Milford  was white , had no Native American  blood .