A civilization is a group of people who farm and hunt as a group
No. Tradition holds that it started around 2000 BCE, but archaeological evidence goes back to 1600 BCE.
Yes there is a cast system in America; they just don't call it that; But people in America are divided in to supersticious religious casts: Protestant; Catholic; Baptist; Muslim, ect. As long as belief, the great divider, is accepted as truth; There Will Always Be Casts. And civiliization will exist on the brink of disaster; for it is written: Every Kingdom divided against itself is bought to dessolation; Every city or house divided against itself, shall not stand. [MATTHEW 12:25.] Civilization is not execempt from His law