I don't think John Louis Graham & Mary Ellen McMillian are the parents of Oliver Sharp Graham.

There are several items on the internet about John Louis Graham,who died Sept. 1863 at Chickamauga. One item is found at Nemaha County Part 12. It states that Capt. John L Graham who died on Sept. 1863, at Chickamauga was one of the original settlers of Albany, Nemaha Co KS. He was born in Richford NY, married Nancy J Slosson on Apr 7 1853 in Maine, Broome Co NY. He left 2 sons, Charles D & Fred E. Graham Co KS is named for Capt. John Louis Graham.

I don't think there were 2 John Louis Graham who died on the same day at Chickamauga.

I believe Oliver S Graham's parents were P H (Payton/Peyton) Graham and Margaret _______? Barham, widow of John D Barham of Dade & Greene Co MO. PH Graham & Mrs. Margaret Barham married on 14 Jan 1858 Greene Co MO Bk B pg 141. John D Barham died after 10 Apr 1856(when he bought land in Greene Co MO)& before Jan 1858.

1850 Dade Co MO census, Dist 25, dwl 653 fam 664 lines 28-32
John D Barham 33 b KY (name listed as Barone on census, have posted correction)
Margaret Barham 23 b TN
Hellen Barham 7 b MO
James Barham 4 b MO
Isaac Barham 0 b MO

1860 Greene Co MO census, Center Twp, PO Bowdark (Bois D'Arc)pg 236 sheet 62, dwl 417 fam 417 lines 1-7
P H Graham 29 b KY (name spelled Greyham on census pg)
Margaret Graham 35 b TN
Hellen M Barham 16 b MO
James H Barham 14 b MO
Isaac Barham 11 b MO
Oscas L Graham 1 b MO (this is Oscar-name spelled Grayham
on census pg)
Oliver S Graham 6/12 b MO (name spelled Grayham-census pg)

Payton's brothers Seth T & V (Volney)A Graham were also on the 1860 Greene Co MO census, pg 241 Cass Twp, dwl 452 fam 457. They were sons of Levi Graham Jr & Mary Tatum. Also in this hhold is their cousin John N. Tatum.

Margaret, her 2 Graham sons, Oscar & Oliver & son Horace Barham are on the 1870 Greene Co MO census,Center Twp, pg 169, dwl 2042 fam 2023, lines 2-5.

Margaret, her 2 Graham sons, son Horace Barham & his wife are on the 1880 Montgomery Co KS census, Sycamore Twp, pg 347A, dwls 219 & 220 familes 248 & 249, lines 35-39. Horace Barham's name was Isaac Horace Barham.

Oscar, his wife Emily & their family along with Oliver S Graham are on the 1900 Chautauqua Co KS census, Harrison Twp. They are on pg 48, dwl 88 fam 88 lines 14-22. Oscar Graham age 41 b Nov 1858 MO. Oliver S Graham age 40 b Jan 1860 MO. Their half brother, Isaac Horace Barham, & family are on pg 49A.

Oliver S. Graham & family are on the 1910 Kay Co OK census, Beaver Twp, Hardy Town, pg 13, dwl 116 fam 116 lines 31-37.

Oscar L Graham & family are on the 1910 Osage Co OK census, Big Hill Twp, as is their half brother Isaac H Barham.

Oliver S. Graham & family, Isaac H Barham & son are all on the 1920 Osage Co OK census, Foraker Town & Twp.

We don't know if Payton/Peyton H Graham & Margaret ____? divorced or if he abandoned her & the children. He went to AR to live next to his father & his father's 2nd wife & family. Payton/Peyton Graham married two more times. He's on the 1870 Sharp Co AR census. And on the 1880 Pope Co AR census. He was deceased by the 1900 census as his 3rd wife is listed as a widow on this census, Boone Co AR.

John D. Barham was the son of James F. Barham & Margaret Holbrook. James F Barham was the son of James Barham, one of the last 6 surviving Rev. War veterans, & Prudence Freeman, widow of John Dunn of Wake Co NC. James Barham, Rev. War veteran, died in Greene Co MO, 1865. Prudence Freeman Dunn Barham died in Logan Co KY, 1815.

The Barhams were from VA. Moved to NC, lived in Wake, Guilford & Stokes Co's. They moved to Logan Co KY. Some of them moved to Calloway Co KY, others moved to Henry Co TN. Then some moved to Greene, Dade & Polk Co's MO. One Barham son moved to Nevada Co AR.

The Barhams had close ties to the Dunn, Tatum, Graham & Robinson families of NC, KY & MO. I do know that the Graham family of NC & KY had ties to the McMillian/McMillen/Millan family of KY & MO.

Hope this helps.