Okay! Now I get it.

Folks who lived in old Jersey which is an island in the Channel Islands (Between England & France) were good at knitting so they made these woolen garments. And then some folks from old Jersey migrated to New Jersey which is near New York. And those folks kept knitting these woolen garments. And eventually some of those folks who migrated from old Jersey to New Jersey showed some corporate folks the knitted woolen garments that they had knitted. And the corporate folks figured they could make a buck or two or three or more selling these woolen knitted garments that the folks from New Jersey had showed them. And the corporate folks were so pleased at finding a new way to get more bucks from the John and Jane Q. Public that they named these woolen knitted garments after that where these folks who knitted those garments lived which is the state called New Jersey which is named after that island inthe Channel Islands (Between England & France).

But sometime along the way for some reason, the knitted woolen garments called jerseys stopped being knitted woolen garments.

I guess that's what's called progress.