I also am searching the right Samuel T. Houston.
What I have may help you.
There were three Samuel Houstons in Georgia at this time.
Samuel T. Houston, Sr was born on 26 April 1811 in Duplin County, North Carolina. (Samuel T. and Esther Houston's Family Bible Records published in DAR , Georgia Chapters, Vol. IV, OLD BIBLE RECORDS AND LAND GRANTS.)
Houston Bible Records give Florida as the birth place of Samuel T. Houston. All census records, 1850 and later, reported North Carolina as place of birth. All reported place of birth Duplin County, North Carolina. 1880 he reported both parents born in North Carolina. Baptized 25 Sept. 1839, Randolph Co., GA (Bethel Mission, Baptist Chapel) Died 4 March 1881 in Sarepta, Webster Parish, Louisianna. Buried in Sarepta, LA at Missionary Baptist Church Cemetary.
Easter Martin(born 14 FEB 1819 in Union Co, South Carolina) Married Samuel T. in Randolph County and resided there in 1836, just prior to them showing up in Early County, GA. Before 1850 they returned to Randolph County to live.
September 25, 1839, Samuel Houston, Crawford Martin and Isaac T. Houston Called for their letters of dismissal to join another church, November 1839.
These three probably relocated to Early Co., GA together.
Isaac T. Houston is presumed to be a brother of Samuel T. Houston.
CHILDREN WERE:
Robert Barrk Houston, 15 June 1838, Randolph, Ga, died 6 Nov. 1842, Early County, Ga.
Nancy Jane Houston
(Un-named) Houston born on 19 July 1842 in Early County. Died 29 July 1842 in Early Co., GA
Helty Ann Houston born on 2 Oct. 1843 in Early or Randolph Co, Ga, died 12 Oct. 1843 in Early Co, or Randolph Co., Ga.
Mary Eliza (Liza?) Houston born on Sept 3, 1843 in Early or Randolph Co., Ga. Died on 28 Jan 1891 in Colmsneil, TX.
Lazarus Lafayette (Latt) Houston, born 2 May 1847, Randolph co GA. Died 4 March 1931 in Sarepta, Webster Parish, LA. Survived by a wife and ten children.
Henrietta Shuck Houston, born 27 Nov 1848 in Early or Randolph county, GA. Died on 6 Nov 1920.
James Lewis Houston, Born 20 FEB 1855 in Early or Randolph, GA. Died July 21, 1887.
Isaac Decalbe Houston, Born Jan. 4, 1856, Randolph Co., GA. Died Jan. 14, 1896. He married twice.
Dennette Maize Houston, Born 24 March 1857, Randolph Co, GA. Died 7 June 1932 in Shreveport or Sarepta, LA. Resided in Caddo Parish, LA for a period and perhaps died there, was possibly buried in Sarepta, Webster Parish. Residing in Sarepta when he submitted parents Family Bible to Georgia DAR, which published same in 1932. Married three times. Mrs. Minnie May Bryant was likely his third wife.
CHILDREN WERE;
Margaret (Maggie) Houston, born 5 July 1859 in Randolph Co., GA. Died 25 July 1923. Margaret Houston married, Christopher Columbus Martin, her first cousin. He was the son of Robert Martin II.
Martha Houston, born 5 July 1859 in Randolph Co., GA.
Samuel T. (Sammy) Houston, Jr., Born 16 December 1862 or 1852 in Randolph Co. GA.

Hope you can use some of this.
I'm searching Samuel T. Houston, father of Louiza Jane Houston, mother of Lassie Lee Barrow b.1895, (married Andress) let me know if you find Samuel coming this way.
If you don't have early history of Houstons, let me know. Be glad to share.
Joan Snell
snelljosh@aol.com