Perhaps you are stuck in some weird loop due to attending school in different states, or have attended really lousy schools.

When i was in elementary school in NYC, we learned about ancient civilizations and NYC history in 4th grade -- the ancient part was kicked off with a field trip to the Egyptian artifacts at the Met.

In high school in upstate ny, we studied global history and current events from grade 9 through 11. The Chinese portion sucked -- we basically covered the opium wars though the cultural revolution, but we studied many aspects of global history.