I posted this one at GenealogyWise:

This record is for my grand-uncles Carl Manson and Otis Preston Manson (who was known as Preston.) It’s signed by my great-grandfather, Otis Manson (1871-1950).  The historical ironies reflected here is that the school trustee who also signed the card, Daniel Henry Sanford, was the grandson of Reuben Sanford (1796-1846), whose family owned as a slave my gg-grandfather Billy Sanford (1809-1916). They “acquired” him in Virginia, took him to Tennessee when they moved there in 1819, and finally brought him to Texas when they moved again in 1854. Billy Sanford was the father of my great-grandmother, Otis’ wife Betty Sanford Manson (1872-1955).