At first, almost every villager was a farmer. As farming methods improved, farmers produced enough to feed thousands of people, which allowed some of them to do other kinds of work. They became merchants, traders, and craftsmen. Villages turned into towns, and some towns turned into cities. By 2500 B.C., the Indus civilization was large enough to have two major cities—Mohenjo-Daro and, 400 miles to the northeast, Harappa.