I've always wondered when each state banned concealed carry and I'm shocked that no one made an attempt to document and tabulate it until now. It's a work-in-progress, but it's one heck of a start. This is a groundbreaking collection of research, as far as I am aware.
This is only possible due to the advances in technology that have scanned in thousands of law and statute books from across the country.
This will allow me and other researchers to begin to look deeper into the reasons for bans and their effect. For those that don't know, concealed carry was often banned while open carry wasn't. Concealed carry had ties to violence and was so tainted by murder that it became maligned, even though most people who carried did so concealed, even 150+ years ago. I'm oversimplifying, but hey, if you want details, pay me to write my book faster.
The citations are a mess and not in a proper style, but are suitable for expedient research purposes at this informal stage. Also the graphic does not accurately represent territorial and state boundary evolution totally accurately.
These dates are the best I could find. Some I am solid on, others not so much. I've noted where I feel unconfident in the source or where I have not been able to do an exhaustive search to rule out prior laws (primarily in New England and the Northeast). Where possible, I tried to find the actual code/revised statutes and the actual act itself. After the 1920s, research began to get sketchy and often overlapped with the Uniform Firearm/Pistol Acts that became popular. Sometimes I accepted a source if it cited when the law was adopted and there was nothing earlier to be found.
Certain laws are not taken into account, but may be mentioned for research purposes.
None of this is intended to be exhaustive.