Hognose snake isn't venomous. It's saliva is where the toxins are. They don't inject anything. They just have long back teeth. And no, there are not more deaths from copperheads. It is a rare thing to have somebody die from a Copperhead bite. If death does happen, it is normally from not getting to a hospital or the person was young, old, or already had health issues. Copperhead deaths are pretty rare.
Copperhead bites very, very rarely result in human deaths, even though they do account for the most bites by venomous snakes in the US, owing to their very wide natural range and their habits, which often bring them close to human habitation and result in them being stepped on by people who don't even see these well-camoflaged snakes until it's too late. There are actually only two documented human deaths resulting from a Copperhead bite, and both of these involved elderly people with a long history of medical issues prior to the bite itself, and in once case, involving an elderly woman, there is the question of hospital error. The woman, who had a known history of heart disease and was taking medication for this, was treated with pain killers, Benadryl and anti-inflammatory drugs at the ER and sent home, where she later died of a blood clot. It is considered standard protocol, however, NOT to administer antivenin to victims of Copperhead bites, due to the risk of dying from a reaction to the antivenin inself, even the Cro-Fab antivenin, is greater than that of dying from the bite. Instead, doctors do typically treat each symptom, such as swelling and pain, separately. The species of venomous snake responsible for the most human deaths in the US is the Western Diamondback Rattlesnake, another wide-ranging and irritable species which injects large amounts of venom in most cases.
This statement is incorrect. The western diamondback rattlesnake is responsible for the most deaths in the U.S. That being said, all venomous snakes, including copperheads, deserve to be treated with caution and respect.
That's typically why I hate using common names. Too many people get them mixed up all the time. And, to be honest, I couldn't really tell you the difference right now anyway.