Washington's first doubts about slavery were entirely economic, prompted by his transition from tobacco to grain crops in the 1760s which left him with a costly surplus of slaves. As commander-in-chief of the Continental Army in 1775, he initially refused to accept African-Americans, free or slave, into the ranks, but reversed this position due to the demands of war. The first indication of moral doubt appeared during efforts to sell some of his slaves in 1778, when Washington expressed distaste for selling them at a public venue and his desire that slave families not be split up as a result of the sale.