Taxonomically speaking, all deer belong to the order Artiodactyla, better known as even-toed animals. Including dewclaws, deer have four toes per foot. They belong to the class Mammalia, or warm blooded mammals, and also fit the phylum Chordata, better known as animals that have backbones. If we continued to classify deer, we'd say they belong to the suborder Ruminantia because they are ruminants or cud chewers with a four chambered stomach that facilitates digestion. As mentioned, they are members of the deer or Cervidae family, and specific to the American continent fall under the genus Odocoileus, more specifically mule and white-tailed deer.
Further breakdown shows that the whitetail owns the species name virginianus exclusively.
Time, regionality and distribution have allowed us the opportunity to take our taxonomy even further by giving whitetails in North America a trailer or tag at the end of the usual scientific name Odocoileus virginianus. It is interesting to note that science has offered some explanation as to the differences denoted by the subspecies tag, as deer are most often classified according to their size, weight, region they populate, color variations, and diet. Some basic rules to keep in mind when considering a whitetail subspecie are Allen's Rule and Bergmann's Rule. Allen's Rule - Simply stated, this biological principle says that in the more northern ranges of the whitetail, regions likely to be colder, the outer parts or extremities of a deer, including legs, tail, and ears, tend to be shorter than in the regions of the south where the climate is more mild and warmer, and where deer more often have larger or enlarged legs, tail, and ears. Their geographic success is most likely a product of evolution, genetic superiority, wary behavior, adaptability, and improved range.