USA HISTORY

Detailed explanation-1: -The first cities appeared thousands of years ago in areas where the land was fertile, such as the cities founded in the historic region known as Mesopotamia around 7500 B.C.E., which included Eridu, Uruk, and Ur.

Detailed explanation-2: -The Degree of Urbanization identifies three types of settlements: Cities, which have a population of at least 50, 000 inhabitants in contiguous dense grid cells (>1, 500 inhabitants per km2);

Detailed explanation-3: -Key Points. The very first cities were founded in Mesopotamia after the Neolithic Revolution, around 7500 BCE. Agriculture is believed to be a pre-requisite for cities, which help preserve surplus production and create economies of scale.

Detailed explanation-4: -The first cities appeared during the Neolithic Period when the development of agricultural techniques assured surplus crop yields large enough to sustain a permanent population. These cities emerged in sites of early civilization, such as the Nile valley, the Indus valley, and the Wei River valley.