Here's what I could find for you...

Sandy Horton married Mina Easley on Dec 17, 1902 - Recorded in Vol G, p 409 of the Panola Co Marriage Records.

According to the 1900 Panola Co Census, Mina was the daughter of Simon and Rebecca Easley. Simon Easley married Rebecca Nickerson on Sep 15, 1872 - Recorded in Vol C, p 277 of the Panola Co Marriage Records.

On the 1870 Census of Panola Co there is no one listed by the surname Easley and neither of the Nickerson families had a child named Rebecca, so I cannot run those names back any further for you. Possibly they were in Harrison Co at that time.

On the 1870 Census of Panola Co there are five African-American Horton families all living next door to each other. They were in the part of Panola Co that is right up against Harrison Co in the vacinity of the Harrison Co city of Elysian Fields. Looking at the places of birth of their children, I would guess that they had been in TX approx 15 years and all the older ones had been born in GA.

The best guess is that their former slave holder had been Thomas Horton who was born about 1828 in GA. On the 1860 Census of Panola Co he was shown as a farmer who had been born in GA. His estate was valued at $28,000. Since land at that time was very cheap, this high value of his estate would had been mainly the value of his slaves. He is not listed on the 1850 Census, but is on the 1860, so that would put him arriving in Panola Co somewhere between those dates. This would coincide with the above guess that the African-American Hortons had been in TX approx 15 years.

The six adjacent households on the 1870 Panola Co Census and the heads of their households were as follows:
HH 1376 - Clark Horton - b abt 1815 in GA
HH 1377 - Sandy Horton - b abt 1841 in GA
HH 1378 - Gaines Horton - b abt 1830 in GA
HH 1379 - Fannie Horton - b abt 1792 in GA
HH 1380 - Austin Horton - b abt 1850 in GA

After the 1870 Census, some of these families must have moved just over the line into Harrison Co as only Clark and Fannie remained on that census.

HH 1377
Sandy Horton - 19 - B/M - Works on farm - b in GA
Dora Horton - 17 - B/F - Keeps house - b in TX
Richard Horton - 14 - B/M - Works on farm - b in TX
Eli Horton - 12 - B/M - Works on farm - b in TX
Willis Horton - 11 - B/M - works on farm - b in TX
Burrell - 9 - B/M - b in TX

There is no official record in Panola Co of the marriage of Sandy and Dora. However, it might be assumed that Dora died shortly after this census as Sandy Horton married Alpha Jeter on Nov 6, 1871 - Recorded in Vol C, p 302 Panola Co Marriage Records.

Looking in the 1870 Census of Panola Co, Alpha was the daughter of Alexander and Harriett Jeter. At the time of the census she was only 13 years old and had been born in TX. Therefore, she would only have been 14 when Sandy married her, so it is quite possible that the Sandy Horton, who was old enough to marry in 1902, could have been her son by the older Sandy.

Since the old Sandy Horton and Alpha were not on the 1880 Census or the 1900 Census, they must have still been in another county, possibly Harrison. They weren't far out of Panola County as the younger Sandy came back into Panola to court and marry.

If you live close enough to Panola County to go with me and help me index the African-American cemeteries all along the Panola -Harrison county line, it is possible that you might find a real treasure trove of information about your family.