I’ve noticed a trend in American media to make fun of New Jersey (typically treating it as hell on Earth). How did this come about? We don’t have any animosity towards its namesake over here in Britain at least.
It had the misfortune of winding up with many of the less salubrious municipalities in the greater NYC metro area, without getting any of the cachet attached to New York, since the city itself is in another state. A similar situation exists with Philadelphia.
Q: Where did the jokes about New Jersey being a horrible place come from?
A: People who have been there. 
Much of the image problem is due to the fact that the part most people see, the New Jersey Turnpike between New York City and Philadelphia, is lined with smoke-belching, stench-spewing chemical refineries and other industrial sites. Also, many of the communities adjacent to New York City such as Newark were subject to serious urban blight in the 1960s.
Two transplanted British folk singers, John Roberts and Tony Barrand, used to sing The Rolling Mills of New Jersey at the university where I went to school in the 1970s.
To the tune of The Rolling Hills of the Border:
New Jersey suffers from being the downriver suburbs of two of the largest cities in the nation: New York and Philadelphia. And it’s downwind of the area that was the heart of the Industrial Revolution. Not to mention taking a strong role in the industrial revolution itself.
Immigrants into New York or Philadelphia were often sent to live across the river if they were of undesirable ethnicity.
In the 1970’s it was considered one of the most polluted states, both air and shore. - which resulted in a lot of clean up efforts to get the area back to the not-so-bad condition it’s in now.
But New Jersey is still the “wrong side of the river” from a significant percentage of the United States population. And Neither New Yorkers or Philadelphians are known to keep their opinions to themselves.
We have done this one a couple of times. Here is a good thread on it. My answer was:
"New Jersey is the most densely populated of the U.S. states although it does have some semi-rural areas and farms in parts of it (its motto is The Garden State which many people find odd). Much of the humor poking is because all many people see of it is from driving down the New Jersey Turnpike out of NYC. The area around the turnpike is uber-industrial which belching stacks and concrete and steel everything. The joke when somebody says they are from New Jersey is to say “What Exit?” (like the user here) insinuating that all of New Jersey is found right off the turnpike.
Other factors include the fact that some of the cities outside of NYC like Camden and Newark have reputations as crime-ridden armpits. People from NYC itself often lump everyone in the New Jersey suburbs as living in a hellhole. The people of New Jersey are thought nationwide to rude and warped by their rather unique environ compared to the rest of the nation. People in the U.S. tend to be fascinated with the Mafia but place associations with it aren’t really positive. Then, there is the rather brash Jersey Shore and Atlantic City (gambling). It all adds up in the popular mind to be something that isn’t quite elegant or attractive.
Parts of New Jersey are indeed beautiful like Princeton where the university by the same name resides. Most people don’t think of those parts first however when New Jersey is mentioned."
http://boards.straightdope.com/sdmb/showthread.php?t=397083&highlight=jersey
New York is a center of American media, so perceptions of New Yorkers are often promulgated in mass culture.
People who live in Manhattan will often never do anything in New Jersey except drive through it on the New Jersey Parkway. The parts of New Jersey that can be seen on the parkway are mostly industrial parks, factories, and other unpleasant views.
Add this to natural regional rivalry and cultural prejudices and Manhattanites collect images of New Jersey being related to philistinism (big hair, bad fashion sense, horrible accents) and other stereotypes (organized crime), and you’ve got the whole ball of wax.
They are not all critical of NJ. For example:
Q: Why does New Jersey have the most toxic waste dumps, and California the most attorneys, of all of the states in the union?
A: Because New Jersey had first pick!
Agreed.
But seriously, I think you all are over thinking this. It’s common for people to make disparaging jokes about their geographical neighbors. Folks in Cincinnati make Kentucky jokes. Folks in Wisconsin make fun of folks in Minnesota. The whole north/south things… it’s just the humor of “the other.”
“Deep in the Heart of Jersey” by Cowboy Charlie from NJ’s own “Uncle Floyd Show”. 
However, because of the proximity of New York City, jokes about New Jersey are far more prevalent than those about most other areas. The OP is in Great Britain. I suspect he has heard very few jokes about Kentucky or Minnesota.
North Jersey (New York burbs) gives the whole state a bad name, and most people who get only glimpses of New Jersey are seeing North Jersey’s lowest forms of everything.
The rest of the state has spectacular shore lines, intercoastal waterways and farm land. Cape May County is pure heaven.
That’s because folks in Minnesota have a sense of humor. We gave up telling jokes about Illinois because they don’t.
And they were considering making that the state anthem.:dubious:
There was an article in the NYT a couple of days ago about the Phillies taking the train to NYC from Philadelphia.
There was one line in it that totally made me smile -
In between Philadelphia and New York City, there’s a whole lot of New Jersey. And it is beautiful. 
yah, I haven’t done a poll, but you don’t find the word “suicide” in too many state anthems.
It being GQ I’ll quibble about this. There is no such thing as the New Jersey Parkway. There is the Jersey Turnpike and the Garden State Parkway, and the part of the Jersey Turnpike you see when you get on it from New York and head south is the cause of the slanders.
I think I’ve seen a quote from Einstein about Princeton being a city pretending it is not a part of New Jersey, so this has been going on for a while. (I can’t find it online.) As a former Princeton resident, I much prefer the scenery there to most of California.
Q: Where did the jokes about New Jersey being a horrible place come from?
A: The services of an Optometrist?
New Jersey doesn’t have a state anthem. It’s the only state in the Union without an official song, actually.
I started a similar thread a few months ago. I’m from New Jersey, and the place where I live seems pretty nice to me.
If you work in Secaucus and don’t mind a daily 1.5 hour commute (each way), you could do a lot worse than living in Sussex County up in the “Skylands” part of New Jersey. Very hilly, with scattered farms in the valleys, along with the exurban and vacation cottage-y towns and developments. And Princeton is quite lovely too, smack in the middle of the (non-freeway) drive between NYC and Philly.