Based on Davidsons chapter and your own research (scholarly, of course!), what role did land play in American history? Was it as important as Davidson makes it out to be?

Based on Davidsons chapter and your own research (scholarly, of course!), what role did land play in American history? Was it as important as Davidson makes it out to be? Would the United States have become the cultural, financial, and military nation it is today if it had covered only from the Atlantic Ocean to the Appalachian Mountains?