What were some of the differences between the British and American pop scenes in the 1950's and early 60's?

The British pop scene in the mid-1950s was influenced by skiffle (which had originated in the US). Skiffle was a forefather of the blues-influenced British bands.

The only differences I can think of is the degree of popularity and even that's suspect in regard to the cuts (especially 45s) because a 45 wasn't necessarily released at the same time on both sides of the pond thus up against different competition. Plus, sometimes the "B" side was different. Black artists like Little Richard and Chuck Berry were played extensively in the states.

I think during the 1950s pop music was mainly from America. Guys like Buddy Holly, Elvis, Jerry Lee Lewis, Ray Charles,  Bill Hayley and the comets, Chuck Berry, little Richard, James Brown etc..  In the 1960s the British music invasion began with musicians like Gerry and the pacemakers, the Animals, Herman's Hermits, and some of the greatest bands ever such as the Beatles and the Rolling stones.  American bands were still pumping out the hits but by 1964 the Beatles were the number one band in the world.  These days American bands tend to dominate the music scene but in the 1960s the British bands were very strong and popular.