I think that this is one of the beggarticks, in the genus _Bidens_. There are several possibilities in your area, including _B. connata_, _B. frondosa_, and _B. vulgata_. I think more detail would be needed for a finer identification.
The main features pointing me this way are the opposite, compound leaves, and the distinctive shape of the leaflets (ovate-lanceolate, serrated margins, attenuate tips).