sorry it took so long to answer you ! the american crow (any corvids in america to my knowledge) are protected by the migratory bird act however there are non native species for sale such as the pied crow and i think there's another the hooded raven but they can be pretty expensive there is an alternative though like getting a baby starling they act just like crows with their mimicking abilities, personality and i think feeding requirements all in a smaller package i hope this helps !
Exactly what cmberger929 said... It is illegal to keep any north american species. The African Pied crows and the Carrion Crows (as well as the Ravens) that are available are imports raised for the exotic pet trade. They are large messy birds(wet squirty poops), require a minimum indoor enclosure of the largest Macaw cage available(for nighttime only), a large outdoor aviary, and many people meet their needs better by dedicating and entire spare room of their home for them. They also have very specific dietary requirements.
As awesome as the corvids are, they are a handful. I suggest LOTS of research into them before making any decision.
I've done it, am still keeping up with research, advice, and breeders(I specifically want an African Pied)... and I know I'm not ready to provide a proper environment yet.