Jersey-Dweller is a slur used to describe Blacks in a derogatory way. New Jersey = the arm pit of America, this does not mean that African Americans live in Jersey. However, in any city in America, African Americans can be found in the worst parts (or arm pits) of that city. Therefore making them Jersey-dwellers.
The word Jersey-Dweller is a racial slur that has been used historically to degrade and dehumanize blacks. The word is still used by some people for this purpose, and it is seen as offensive and hurtful to blacks. If you are unsure about whether or not it is appropriate to use the word Jersey-Dweller, it is best to err on the side of caution and avoid using it in any situation.