Though the Code of Ethics may not have been developed for a few years after Mr. Betts's death. Honesty and not hiding critical documents couldn’t have been outside the expectations for one calling themselves a historian as he did.
Slavery did exist in many parts of the world, some of his fellow founders never owned slaves, John Jay inherited slaves yet got rid of them during his lifetime and helped to abolish slavery in the state of New York. Jefferson said several things over the years suggesting an aversion to slavery, but how can we give them more credit than his actions? His letter to Washington made it clear he understood the value of slaves. His role in improving the profitability of slave breeding showed he was all in for slavery despite his words which inevitably meant little.