New York

New York is known for being a busy state with lots of angry inhabitants.
This stereotype is because of the single city within New York of New York, which includes five areas named Manhattan, Brooklyn, Queens, the Bronx ans Staten island;
As a single city this is strange compared to most in america because its near impossible to drive from one area to all of the others as most of them are split by rivers. Manhattan (navy blue on the map) being the relatively small one which is surprising due to often how this area is often the only one mentioned. Staten island (purple) is well named in the fact it is completely deserted from the rest of New York without boat travel.
The state of New York itself has a very centered population similar to the other states already looked at in this blog; A picture of the population density would look like the picture below (source: www.dec.ny.gov) with New York city being only the small red part at the bottom

New York, having the advantage of having being not only one of the first colonies of the us but it is one of the early European settlements in america, having being first founded by the Dutch under the name of New Amsterdam in 1626, then taken over by the English in 1664 and being renamed New York. Because of this New York city, and to a lesser extent New York state have had the opportunity to build an almost unbeatable reputation for business tycoons to go to make millions, Wall Street being just one example of the many locations in NYC to do this. Add this to a rich culture of history and art that typically wealthy people enjoy and the fact that the city is just one state over from Harvard University  thus attracting many promising young graduates at the top of their game to increase competition between candidates and cooperation's which leads to both skilled workers and better value products/larger profits (depending on the type of company). A booming economy is a result of this. 

All of what I just described leads to a stereo typically impatient population because these wealthy business men are, almost by definition, busy people, and stress levels easily run high among them. The phrase 'time is money' is particularly relevant here, and so any reason for them to be held up by even a second by for example; traffic, public transport delays or even someone walking slowly on the street  causes these people to get angry at the delay and thus New Yorkers have their reputation of being angry people.