By the end of the colonial period, the number of enslaved people in Delaware began to decline. Shifts in the agriculture economy from tobacco to mixed farming resulted in less need for slaves' labor. In addition local Methodists and Quakers encouraged slaveholders to free their slaves following the American Revolution, and many did so in a surge of individual manumissions for idealistic reasons. By 1810 three-quarters of all blacks in Delaware were free. When John Dickinson freed his slaves in 1777, he was Delaware's largest slave owner with 37 slaves. By 1860, the largest slaveholder owned 16 slaves.