In many eastern U.S. states whitetail deer harvest regulations are quite liberal. In most of them you can take at least two deer or more per season. Usually, one or both can be an antlerless deer while only one can be antlered. Some states allow the taking of multiple bucks per year.
You'll find the best overall age structure (read older bigger bucks) in states with more restrictive buck regulations. In states where hunters can take many does but only one buck (like here in KY) there are more older bucks in the population.
Per square mile of deer habitat, KY is usually ranked number 2 in the U.S. in terms of Boone & Crockett bucks with 50+ per year making the BC book. However, these big deer are still rare finds and even more rare harvests, especially with archery gear.
Some other famous whitetail states have other reasons why large deer are commonplace. Most have to do with the length and timing of the firearms season. If the firearms season is brief (IL) or timed later than the rut, bucks survive to an older age.
Our season is very long starting on the 1st Saturday in September and ending the 3rd Monday in January. The license fee is $130 for general hunting and $60 for the deer tag. The tag allows two deer to be taken over most of the state. The tag can be used with whatever equipment is legal during the particular time of the year: Archery, Muzzleloader, Handgun, Rifle, and XBow.