No relation to Russell, the American Crow is a pretty smart bird. From Cornell’s site we read “Crows sometimes make and use tools. Examples include a captive crow using a cup to carry water over to a bowl of dry mash; shaping a piece of wood and then sticking it into a hole in a fence post in search of food; and breaking off pieces of pine cone to drop on tree climbers near a nest.” 
The American crow is all black, with iridescent feathers. They can be distinguished from the Common Raven because American Crows are smaller, and from the Fish Crow because American Crows do not hunch and fluff their throat feathers when they call. 
The most usual call is a loud, short, and rapid caaw-caaw-caaw. Usually, the birds thrust their heads up and down as they utter this call. American crows can also produce a wide variety of sounds and sometimes mimic noises made by other animals, including other birds.  We think crows have a call that sounds like “uh oh, uh oh” and at least one person in this house has become a crow mimic.
They move in groups, usually in the tops of trees. They will collect in a group and ‘mob’ and a potential predator, and you can read about one example of this on our page about the Great Horned Owl. On a visit to St. Simons one afternoon, we watched a group of crows dive bomb a large hawk (Red-tailed or Red-shouldered) in the top of a tall pine and then follow up by trying to dismantle an Osprey nest. Pretty gutsy on both counts.
A group of crows is called ‘a murder of crows’. Where does the term ‘murder’ come from? Probably from old folk tails and superstitions. One of the tales is that crows will gather to determine the fate of another crow. 
Crows are actually very social birds. They will gather in flocks as large as a thousand, mainly to protect themselves from their enemies. 
References and Additional Information
 Wikipedia: American Crow
 The Sibley Guide to Birds, second edition – David Allen Sibley
 Cornell – All About Birds: American Crow
 Cornell – All About Birds: American Crow – sound
 The Breeding Bird Atlas of Georgia – UGA Press: Schneider, Beaton, Keyes and Klaus, Eds.
 Cornell – All About Birds: American Crow – life history
 PBS: Crow Facts