At 4,132 miles (6,650 km.), the Nile River is the longest river in the world. It has its origins in Burundi, south of the equator, and flows northward through northeastern Africa, eventually flowing through Egypt and finally draining into the Mediterranean Sea. Three principal streams form the Nile. In Ethiopia's highlands, water flows from the Blue Nile and the Atbara. Headstreams of the White Nile flow into Lake Victoria and Lake Albert. The Nile River basin is immense and occupies an area about one-tenth of the continent of Africa. It includes portions of Tanzania, Burundi, Rwanda, Zaire, Kenya, Uganda, Ethiopia, The Sudan, and Egypt. It is estimated to drain an area of 1,293,000 square miles (3,349,000 sq. km.)
The Nile receives its name from the Greek Neilos, which means a valley or river valley. The river flowed northward and flooded the lands in Egypt, leaving behind black sediment. As a result the ancient Egyptians called the river Ar or Aur (black). The Greeks and Egyptians also gave the land its oldest name Kem or Kemi, which also translates into black. The river's water and the fertile soil along its banks created the perfect setting for the evolution of the civilizations that existed in the ancient world. The ancient peoples that lived along the river's banks cultivated the art of agriculture and were one the first to utilize the plow.
Throughout the year, the Nile serves as a constant source of water. This enables farming along its banks in spite of the high temperatures that occur. In those regions, especially The Sudan, where there is enough rainfall to support cultivation, the high temperatures evaporate enough of the water making irrigation necessary. In addition to its vital role in agriculture, its waterways also play a major role in transportation. During seasonal flooding it enables transportation to those areas where road access is not possible.
During the 20th century, dependence on the waterways as a sole source of transportation has been reduced as facilities for air, rail and highways have expanded.