On Jan 17, 2010 I was lucky enough to be in the Angelina Nat'l Forest. This area covers both Angelina and Jasper Counties. My cousin knew where the old Rockwall [Union] Cemetery was so I got him to veer from his purpose and take me to the cemetery. This African-American Cemetery is on a hill side. I was able to only photograph about 32 due to the time constraints.
You can see the memorials on Findagrave: Rockwall Cemetery
This area was called (and may still be by the locals) as the Boykin Settlement and my understanding is that much of the land was part of the Boykin Planation. After the Civil War, many freed slaves stayed in the area, took the Boykin surname and their desc still live there today.