(Canadians feel free to participate)
In this salad bowl culture of ours, it's easy to overlook or under-appreciate things that were born here, in the States.
Here are some of the American contributions I find most valuable/enjoyable. Feel free to share yours; be they artistic contributions, technological innovations, toys, consumer products, culinary styles... whatever.
MY #1: Rock N' Roll
While the British took it to new levels, it was born here; a culmination of Country, Gospel and Blues (all of which ALSO originated here) combined with the spirit of a restless youth in a transient, yet progressing world. The face of music globally, and the cultures who love it, were shaped by young Americans in the 1950s.
I LOVE the Beatles... but they wouldn't have even existed, at least not as we know them, were it not for early American Country and Motown.
The "Traditional" Tattoo
Tattooing had been practiced for countless years in countless cultures before reaching the Sates... but it was Americans who originated the "Traditional" or "American Traditional" tattoo style which has become a tattooing staple the world over, not only because it's ideal for executability and longevity; but because the traditional American tattoo movement brought tattooing to the mainstream.
Aside from documenting an important time in our (American) history and representing a people that deserve representation, it spawned some great innovators and stylistic evolutions, all of which are still recognized/in use today. Tattooing the world-over would not be what it is were it not for the styles that were born and the strides that were made in America.
Oatmeal and porridge had been served hot in Europe for years, but it was an American who decided to serve oats cold, with milk. The Kellogg family took the idea, made it consumer-friendly and marketed it... creating one of the greatest things ever, ANY time of day: fucking CEREAL. It has a whole aisle dedicated to it.
Not to mention all the variations that have arisen, the idea to put prizes in the boxes, the fun shit ON the boxes... how much of my youth was spent over a bowl of cereal while reading its box? A lot. Cereal kicks ass.