Looks like spreading chervil, Chaerophyllum procumbens. Should have small white flowers.

The leaves look like mugwort (artemesia vulgaris) but lack its silverish cast, Hope, for your sake it is not.

Yeah, but Chaerophyllum is a much more delicate plant, only a foot tall or so, and foliage is finer. There are other little umbellifers that look like that, however, and you would like to see flowers and fruit to make a positive I.d. Sarah's remark "almost like parsley" is very true. I don't see it much in New Jersey, mostly in woodlands where there has been some disturbance. Wait to see what the flowers look like; check pictures on line. Never heard of it being a real problem. I learn something every day. I've no idea how to control it.