Washington, in his will freed all of his slaves when Martha died:
https://www.mountvernon.org/george-washington/slavery/washingtons-1799-will/
In accordance with state law, George Washington stipulated in his will that elderly slaves or those who were too sick to work were to be supported throughout their lives by his estate. Children without parents, or those whose families were unable to see to their education were to be bound out to masters and mistresses who would teach them reading, writing, and a useful trade, until they were ultimately freed at the age of twenty-five. Washington’s will stated that he took these charges to his executors very seriously: "And I do moreover most pointedly, and most solemnly enjoin it upon my Executors...to see that this clause respecting Slaves, and every part thereof be religiously fulfilled at the Epoch at which it is directed to take place; without evasion, neglect or delay, after the Crops which may then be on the ground are harvested, particularly as it respects the aged and infirm."