The association you refer to has been changed to the Thompson-Choctaw Indian Descendants Association in 1999. It was created in 1996 in Marlow, Oklahoma in order to re-unite the descendants of the three sons of Margaret McCoy-Thompson. Henry (who was married to Priscilla Jackson a full blood Choctaw), Archibald (who was married to Elizabeth Jackson a full blood Choctaw and sister to Priscilla, and who after her death he married his cousin Anna Strong Thompson) and William (married to Elizabeth Jones Mangum a quarter blood Choctaw). Margaret was 1/2 Choctaw and 1/4 Chickasaw the daughter of an unknown full blood Choctaw and Sally McCoy a half blood Chickasaw listed on the 1818 Chickasaw annuity roll. Margaret was married to Henry Butt Thompson. Her grandson William C. Thompson (roll #15995)was responsible for having the Dawes Commission forced to create a supplimental roll for the Choctaw Nation by the Supreme Court. Although not Cherokee, her descendants were also involved with the Texas Cherokees and Associate Bands in law suits regarding the 1836 treaty with the Republic of Texas in 1871, 1914, 1920 and 1948.
Family members along with allied Jones (descendants of Nashoba), Jackson, Spring, Tullos and Magee families started settling in Texas in 1828 and were called Yowani Choctaws by the Republic in 1837. By their surnames the group (minus the Thompsons) are closely related to the Jena Choctaws in Louisiana.
A number did get enrolled as Citizens by Blood but the majority remained in Texas. For more information on that group refere to www.chahta.org