The main feature of the economy in Virginia, Maryland and South Carolina was large plantations growing staples for export, especially tobacco and rice. Outside the plantations, land was farmed by independent farmers who rented from the proprietors, or (most often) owned it outright. They emphasized subsistence farming to grow food for their large families. Many of the Irish immigrants specialized in making rye whiskey, which they sold to obtain cash. In Maryland, by 1700 there were about 25,000 people and by 1750 that had grown more than 5 times to 130,000. By 1755, about 40% of Maryland's population was black.