Believe it or not, there are two William Emanuel McElveens. My ancestor's father was William Emanuel McElveen, father William Emmanuel McIlveen. They lived in Indiantown Williamsburg,
* FamilySearch Wiliam McIlveen (https://www.familysearch.org/tree/person/details/KP9B-367) 31 Aug 2021
* The Spruce Pets (https://www.thesprucepets.com/bedding-for-horse-stalls-1885940)
* William's Plantation is designated in Williamsburg Co., SC Will Book A (1802-1826) www.southcarolinalioneers.net (https://georgiapioneers.com/restricted/SC/scprobate/williamsburg/wm... Aug 2021
* "FamilySearch William Sr. (https://www.familysearch.org/tree/person/details/KGM9-MN8) 31 Aug 2021"
* Williamsburg Co., SC Will Book A (1802-1826) www.southcarolinalioneers.net (https://georgiapioneers.com/restricted/SC/scprobate/williamsburg/wm... Aug 2021
* Family Search james (https://www.familysearch.org/tree/person/details/K2FS-TJT) 31 Aug 2021)
* William's son James in Williamsburg Co., SC Will Book A (1802-1826) www.southcarolinalioneers.net (https://georgiapioneers.com/restricted/SC/scprobate/williamsburg/wm... Aug 2021
* See "Jane" in the Williamsburg Co., SC Will Book A (1802-1826) www.southcarolinalioneers.net (https://georgiapioneers.com/restricted/SC/scprobate/williamsburg/wm... Aug 2021
* See "Mary" in the Williamsburg Co., SC Will Book A (1802-1826) www.southcarolinalioneers.net (https://georgiapioneers.com/restricted/SC/scprobate/williamsburg/wm... Aug 2021
* See "MaryAnn" in the Williamsburg Co., SC Will Book A (1802-1826) www.southcarolinalioneers.net (https://georgiapioneers.com/restricted/SC/scprobate/williamsburg/wm... Aug 2021
* See Margaret in Williamsburg Co., SC Will Book A (1802-1826) www.southcarolinalioneers.net (https://georgiapioneers.com/restricted/SC/scprobate/williamsburg/wm...) 31 Aug 2021
* See in Thomas Williamsburg Co., SC Will Book A (1802-1826) www.southcarolinalioneers.net (https://georgiapioneers.com/restricted/SC/scprobate/williamsburg/wm...) 31 Aug 2021
* United States Census, 1840," database with images, FamilySearch (https://familysearch.org/ark:/61903/3:1:33S7-9YY1-S7TJ?cc=1786457&a... : 24 August 2015), South Carolina > Darlington > Not Stated > image 66 of 107; citing NARA microfilm publication M704, (Washington D.C.: National Archives and Records Administration, n.d.).
* See Henry FamilySearch Henry (https://www.familysearch.org/tree/person/details/M2B8-CNP) 31 Aug 20212
* Williamsburg Co., SC Will Book A (1802-1826) www.southcarolinalioneers.net (https://georgiapioneers.com/restricted/SC/scprobate/williamsburg/wm...) 31 Aug 2021
* Wikipedia Indiantown (https://en.wikipedia.org/wiki/Indiantown%2C_South_Carolina)
* Find a Grave, database and images (https://www.findagrave.com/memorial/82979940/robert-decatur-gregg : accessed 31 August 2021), memorial page for Robert Decatur Gregg (1824–12 Apr 1907), Find a Grave Memorial ID 82979940, citing Hopewell Presbyterian Church Cemetery, Florence, Florence County, South Carolina, USA ; Maintained by Bill Smith (contributor 47682389) .
* Highlanders in America (https://archive.org/details/historicalaccoun00macluoft/page/442/mod.... 442
* "United States Census, 1790," database with images, FamilySearch (https://familysearch.org/ark:/61903/1:1:XHKN-LT1 : accessed 9 September 2021), Wm Mcilveen, Prince Fredericks, Georgetown, South Carolina, United States; citing p. 500, NARA microfilm publication M637, (Washington D.C.: National Archives and Records Administration, n.d.), roll 11; FHL microfilm 568,151.
https://www.familysearch.org/tree/person/details/KP9B-367
There is a second William Emanuel McElveen, I didn't complete this study but his family moved to Sumter SC and later migrated to Mississippi I believe. I'd have to check, but I'm pretty sure that's what we concluded. The two families were differentiated by autosomal matches. The family in Williamsburg was a traditional plantation. The family in Sumter (again from what I remember) raised cattle. We see them being inherited from their subsequent fathers.
If I can attach this ancestor, I will include their sources.
Please advice.