Are possums in New Jersey marsupials?

yes, all possums are marsupials as they lack a uterus

Possums look somewhat like giant rats, with their pointed snouts and skinny, naked tails. They are in fact North America's only marsupial (like kangaroos, they raise their young in a pouch). Adults average 10-14 lbs. They don't live very long, rarely more than two years, three max.The above description applies to the opossum, not true possums. Possums and opossums are frequently confused, but they are not related. True possums are not found in New Jersey, but are native to Australia and some islands of the South Pacific. Possums look noting like giant rats.