Other than the Ruby Throated Hummingbird whose ranges is the entire Eastern half of the US and lower Canada, the Rufous would be the next most widespread. At varying points during the year Rufous can be found from Alaska to Central America, from California to Florida, with occasional sightings in the mid-Atlantic states.
Rufous is one of the more aggressive hummingbirds. I've watched one spend his entire day chasing other hummers away from a particular feeder -- rarely find time for feeding himself.
The male is especially attractive:
|Rufous Hummingbird protecting his feeder from a Black Chinned Hummingbird|