It would hardly be overstating the issue to say that tea has had a considerable influence on the affairs of human beings. If you'd like to explore this issue in a little more depth here are some reading recommendations:
Did Tea and Beer Make Britain Great, is a brief, but interesting article by Alan Mcfarlane which examines the role these beverages supposedly played in bringing about the Industrial Revolution.
I mentioned Tom Standage's A History of the World in Six Glasses a while back, but it's a great book and deserves another plug. Standage has taken a book-length approach to examining the role of six beverages and their influence on the affairs of human beings. Of course one of the beverages is tea (also c*****, beer, wine, spirits and cola).
For another entertaining and offbeat history - one that has nothing to do with tea - you might also want to check out Standage's The Victorian Internet.