British Culture in 1912 versus American culture differences?

PBS "Masterpiece Theater" is showing a 4 part series about England that starts with the sinking of the Titanic in 1912 and the start of WW I. It's really about the different "cles" of people in the UK at the time; even within the household staffs of mansions, etc. It all changed with the war but then there were the haves and the have -nots especially among the working cles. There is a Countess played by Maggie Smith who asks "what is a weekend ?" Because the wealthy did not "work"; they had others who worked for them & kept them happy. Now if anyone saw "Gangs of New York" you would have seen culture cles between those who saw themselves as true American "Bill the Butcher played by Daniel Day Lewis" & Irish immigrants played by Leo DiCaprio & Cameron Diaz. Not talking about slavery here and not about the white vs black vs Asian mentalities. Just about the cles here in American from the 1840s to the start of WWI. I'd like to hear what you thinks of the different "cles" of people in America then versus the British cles of people. Were they just about the same more or less or different? Why do you think the British class system really didn't change until WWII? Have any of you watched Masterpieces' "Downton Abbey" ? It's marvelous. Very thought provoking.