Washington and slavery

For most of his life, Washington operated his plantations as a typical Virginia slave owner. In the 1760s, he dropped tobacco (which was prestigious but unprofitable) and shifted to wheat growing and diversified into milling flour, weaving cloth, and distilling brandy. By the time of his death, there were 317 slaves at Mount Vernon.
Before the American Revolution, Washington expressed no moral reservations about slavery, but, by 1778, he had stopped selling slaves without their consent because he did not want to break up slave families.
In 1778, while Washington was at war, he wrote to his manager at Mount Vernon that he wished to sell his slaves and "to get quit of negroes", since maintaining a large (and increasingly elderly) slave population was no longer economically efficient. Washington could not legally sell the "dower slaves", however, and because these slaves had long intermarried with his own slaves, he could not sell his slaves without breaking up families.[21]
After the war, Washington often privately expressed a dislike of the institution of slavery. Despite these privately expressed misgivings, Washington never criticized slavery in public. In fact, as President, Washington brought nine household slaves to the Executive Mansion in Philadelphia. By Pennsylvania law, slaves who resided in the state became legally free after six months. Washington rotated his household slaves between Mount Vernon and Philadelphia so that they did not earn their freedom, a scheme he attempted to keep hidden from his slaves and the public and one which was, in fact, against the law.[22]
Washington was the only prominent, slaveholding Founding Father to emancipate his slaves. He did not free his slaves in his lifetime, however, but instead included a provision in his will to free his slaves upon the death of his wife. His actions were influenced by his close relationship with the Marquis de La Fayette.
Washington's failure to act publicly upon his growing private misgivings about slavery during his lifetime is seen by some historians as a tragically missed opportunity. One major reason Washington did not emancipate his slaves earlier was because his economic well-being depended on the institution. He did not speak out publicly against slavery, argues historian Dorothy Twohig, because he did not wish to risk splitting apart the young republic over what was already a sensitive and divisive issue.[23]