Its purpose was to generate revenue for the federal government (to run the government and to pay the interest on its debt), and also to act as a protective barrier around newly starting domestic industries. An import tax set by tariff rates was collected by treasury agents before goods could be unloaded at U.S. ports.
The Nile's overflow made for easy farming land. In addition, the Nile could provide easy irrigation and transport of materials.
Answer:
Sumerian, Babylonian, Assyrian and Persian
