It is perfectly well understood...that to educate a slave is to make him discontented
with slavery, and to invest him with a power which shall open to him the treasures of freedom;
and since the object of the slave- holder is to maintain complete authority over his slave, his
constant vigilance is exercised to prevent everything which militates against, or endangers the
stability of his authority. Education being among the menacing influences, and, perhaps, the most
dangerous, is, therefore, the most cautiously guarded against. - Frederick Douglas, 1850
I found this while researching a paper for American History to 1865, enjoy!