When Americans say they are proud of their heritage what is the earliest event they are proud of?

Just wondered where in time american national pride start and what the associated event was: Development of American Indian culture, Spanish colonies in Pacific, French colonies in Louisiana, British colonies in Jamestown, Landing of the Pilgrim fathers, the Boston Tea Party, the war and./or declaration of Independence, the winning of the west, the abolition of slavery, the 2 world wars, putting a man on the moon. You choose.

I think we are proud of most of this. The history we are taught in school usually makes it sound as if America "started" with Jamestown, so I guess that is where most of our national pride starts. This probably varies for different people, however. For example, I feel that winning our independence is when our nation started, though I am proud of most of those events, especially the abolition of slavery.
As for Americans who are proud of their heritage, I think everyone should be proud of their heritage. Every country in the world has some amazing things in their history, and no one is better than any other.