The greatest gift passed on by ancient Greece was democracy, had ancient Rome which was greatly influenced by Greece adopted it or at least remained a Republic instead of becoming enamored with emperors, I suspect they would've lasted longer.
The greatest gift passed on by Native Americans was living in harmony with nature, being connected to the land as an extension of themselves, had the U.S. adopted and stayed with more environmentally friendly or conscious policies, might we and the world have better prospects for the future?
2. I read two books on Greek democracy that will stay with me to the grave
C.L.R. James' Every Cook can Govern and Ellen Meiksins Wood's Democracy against Capitalism: Renewing Historical Materialism
Wood's actually discusses the fundamental differences between democracy in Greece and the US.
The indigenous people's of our planet live in sync with the land - they do not exploit or abuse nature for profit.
What, you don't think continued raping and pillaging of the natural world is gonna give us a better future? Africa is next. It's just sitting there being under exploited by the natives. We'll show them, won't we?