What are the large groups of black birds …?

that tend to travel together, and roost in treetops or powerlines? They make raucous cawing noise and flock in large groups, espescially around dusk.
Are they CROWS, JACKDAWS, ROOKS? I thought they were blackbirds but wiki doesn’t mention blackbirds being indiginous to North America. I’m in MD, if this info helps answer my question.

I’m using this info for a story I’m writing so accuracy and any help you can give is MUCH appreciated.
I know they aren't ravens . They are way too small. I did a whole research report on ravens. And they are in MD
thanks for the links, levirat

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