Talking about contributons, just to set the history record straight, Jin Dynasty China invented Bamboo-copter/dragonfly/Chinese Top around 320 AD, which perhaps is the first tangible device of what people may understand as a helicopter, at that time, 1700 years ago, the USA wasn't even around...
Later, a British engineer, the inventor of modern aeronautics, George Cayley experimented such helicopter concept in 1792, which he later called "rotary wafts" or "elevating fliers" and made improvements. This is a proof that every scientific progress is made by accumulating previous scientific knowledge, i.e. standing on someone else's shoulders.
To mock and belittle other civilisations for their contribution which one has no knowledge about only shows the "shallowness" of oneself. Mind you, both China and Britain have doorknobs older than the entire history of the "good old" USA...
In contrast, the same year 1792, 16 years after her founding at 1776, the USA just passed her first Postal Service Act in Feb, her first Coinage Act in April, constructed the first blast furnace for melting industrial metals in Pittsburgh, celebrated her first Columbus Day in New York, 300 years after his arrival in the New World...
Sorry to hear gambit's definition of so-called "dawn" in the USA comes in so late...