sentences:  The economics of slavery prompted the first doubts in Washington about the institution, marking the beginning of a slow evolution in his attitude towards it.By 1766, he had transitioned his business from the labor-intensive planting of tobacco to the less demanding farming of grain crops.His slaves were employed on a greater variety of tasks that needed more skills than tobacco planting required of them; as well as the cultivation of grains and vegetables, they were employed in cattle herding, spinning, weaving and carpentry.