What was america's most important possession

I would have to say our freedom, independence, and pride.

I say this because it seems that while they're not physical possessions, they seem to be the only things that men, women, teen, children, young and old all across the country are willing to die for any day. It is what our country was founded on, the thought and idea of freedom from Britain, independence from the "mother country" and pride in being our own nation.