What impact did the Beatles have on the us?

The Beatles have influenced what most modern music is today and that influence can be heard throughout pop music today, Robert Greenfield (a once associative editor for Rolling Stone likened The Beatles to Picasso in the way that both broke free from "the constraints of their time period" to create something "unique and original" and that no one in Pop music history will ever be "more revolutionary, more creative and more distinctive". In fact their music was so revolutionary that Ricky Sklar of of New York's WBAC Radio forbid the DJ's from playing anything pre-Beatles.
The Beatles and all of the other British Invasion bands, the Zombies, the Yardbirds and The Tornados all became very popular during the mid 1960's but the interesting thing is that these bands were influenced the most by US acts like Buddy Holly, The Everly Brothers, Elvis, Little Richard, Chuck Berry Motown and the blues genre (the Rolling Stones began as a Blues band). In fact The Beatles would constantly look for new avenues in music and draw inspiration by listening to their contemporaries such as Bob Dylan, The Beach Boys and many others and in turn these British Invasion bands influenced the US acts and changed American music for good.. The Beatles had a profound affect everywhere not just the US - they became icons of the Counterculture of the 1960's and embodied many of the ideals assosciated with cultural transformation; they became catalyst for such radical and necessary movements and campaigns like women's liberation, gay liberation, the Campaign for Nuclear Disarmament and enviromentalism. They became symbols of peace, unity and total-equality everywhere.

Hoped that helped a little.