The Eastern Wolf is the oldest species of wolf in the world. It is estimated that they date back to the Mid-Pleistocene era (mtDNA testing dates them back as far as 750,000 years ago (canis lupus is thought to be only 100,000-300,000 years old). This very old and largely unrealized species of wolf , it wasn’t until 2001 that it was discovered that they are their own species. While “wolves” are generally either “canis lupus” or a “canis lupus” subspecies (including domestic dogs), the eastern wolf is “canis lycaon” and the only true “wolf” that is not a canis lupus (despite the name, the maned wolf of South America is not a wolf at all, but (Chrysocyon brachyurus) but they are a member of the “canine” family (Canidae)).
The eastern wolf today mainly resides in Algonquin Provincial Park (between Georgia Bay and the Ottowa River in Ontario) but have been known to venture into Quebec. It may also be present in very small areas in Minnesota and Manitoba. This is a very small part of what used to be their historical range, most of the eastern 1/3 of Canada and the northeastern USA.
It is believed that there was a lot of hybridization going on with the eastern wolf. Today it is believed that the red wolf (canis lupus rufus or canis rufus) may be a hybrid between the eastern wolf and coyote from about 150,000-300,000 years ago (others believe that they branched off from a wolf-coyote common ancestor about 1-2 million years ago).
Also, it has been proven that most coyotes in the northeastern USA are wolf-coyote hybrids but much more recent, only 10,000-15,000 years ago. It is not clear if it was the canis lupus or the canis lycaon which was the wolf ancestor (or both?).