Well the British Invasion was a second wave response to Chuck Berry, Bill Haley, Buddy Holly,Gene Vincent (as rockers) and of course Blues greats like Broonzy, Son House, Leadbelly (and many more). It was literally the Brits adopting (and clearly expanding / moving forward) American musical ideas. perhaps this was a little more music centered than culture centered , but the youth culture and the music scenes kind of went hand in hand

American culture is becoming the world norm even today. Jeans 'n t-shirt, fast food, supercenter shopping, casual relationships, movies, books, science... While those are clearly broad categories and don't specify anything particularly American, the point is that the United States exports a huge amount of culture, along with tangible goods, that influences the world.