Well, not the first time the fox got into the hen house, what you say is in part true Shawnee tribe were not necessarily friends with the Cherokee even though they did have treaties with one another. But a Vann did, in fact, mary a Native woman who had a Shawnee father (Cornstalk)
In researching of my Vann line,I found the Vann family lived on Horns Creek, Edgefield, SC and that there was a Vann family with native Descendants.
Mary Barnes (born Odom) was born on month day 1697, at birth place, Virginia, to Misahpelewa Big Turkey Cornstalk and Elizabeth Keziah Cornstalk (born Odum). Misahpelewa was born in 1660, in Shawnee Tribe,
Native American Heritage:
1. Holesqua Opeecham "Stream" Cornstalk (Shawnee War Chief)
+ Nonoma
2. Big Turkey Cornstalk
+Unk
3. April Tikami Hop Cornstalk (sister of Old Hop,
all the children were adopted by a cousin, Emperor Moytoy of the Cherokee Nation)
+ Richard Barnes
4. Mary Barnes
+ Edward Vann
5. Edward Ned Vann
+ Mary King (She was the daughter of Squirrel King, Chief of the Savannah River Chickasaws and a Thawakilla Shawnee Woman)
Edward Vann III b: 24 MAR 1763 d: 26 JUN 1854
+ Elizabeth Walls b: 1770 d: 12 DEC 1863
Edward Ned Vann b: 1744 married Mary (King) b: 1743 is the son of Mary (Barnes) b:1720 and Edward Vann b: 1720. An Edward Ned (Vann) and Mary (King) had a daughter Margaret (Vann), Margaret (Vann) Moseley b: 1768 in Edgefield Co, SC, Mary King was the daughter of Margaret Vann Moseley b: 1767 d: 10 OCT 1849 in Edgefield Co, SC, she married Robert D. Moseley b: 1755 d: 1831.
There is another fact of the Time Native American were being killed by the millions, being Native American was dangers so this is the reason you have never been told this story is because the Great Grandparents hid the fact they were Native American.
On DEC, 25th 1816 Robert D. Moseley sold 244 acres on Horns Creek, Edgefield, SC.to move to AL. to receive 40 acres of undeveloped property in AL. Robert and Margaret did this to protect their Children (14). They were well known in Edgefield and lived next door to Edward Ned Vann and Mary King.
They had heard about the Indian Removal and ran for their lives, along with many other Native American Families. Edward Ned Vann and Mary Vann were listed on the Enumeration Roll of 1817
Edward Ned Vann was a very wealthy Peach Farmer on the Savannah River, and the Whites wanted his property.
Cornstalk and Tecumseh were famous for trying to send the Whites back to where they came from, and that's why no one on the Dawes Roll would admit to being Shawnee, much less related to Cornstalk.
When April "Tikami" Hop was 3 years old her parents were murdered by
Catawaba Raiders, and her and her 4 siblings were left there to die,
because no one would take them in. Pigeon Moytoy her aunt's husband, heard about this and went to Hiawassee and brought the children home to raise in the Cherokee Nation. he was the Emperor of the Cherokee Nation, and also related to Cornstalk through his mother and his wife )
Personally, I hae found a lot of information that I am sorting through and there is a lot of it that is about Native bloodlines for the Vann, as to it seems like there are a lot of different tribes, not just Shawnee, as to John Vann II having Shawnee or Cherokee blood it is just as probable that he has both.