Prior to 1980
Vermont No law
New Hampshire 1923
Washington 1961
Connecticut 1969
1980s
Indiana 1980
Maine 1985
North Dakota 1985
South Dakota 1986
Florida 1987
I have no reason to doubt the states and dates that you cited. The Florida battle for concealed carry privileges was the first that garnered significant national attention and one of the first big defeats for modern gun control. For whatever reason, maybe just because the MSM paid attention for the first time, Florida marked the turn in the tide.
Fighting Back: Crime, Self-Defense, and the Right to Carry a Handgun
Ten years ago this month, a controversial "concealed- carry" law went into effect in the state of Florida. In a sharp break from the conventional wisdom of the time, that law allowed adult citizens to carry concealed firearms in public. Many people feared the law would quickly lead to disaster: blood would literally be running in the streets. Now, 10 years later, it is safe to say that those dire predictions were completely unfounded. Indeed, the debate today over concealed-carry laws centers on the extent to which such laws can actually reduce the crime rate.
To the shock and dismay of gun control proponents, concealed-carry reform has proven to be wildly popular among state lawmakers. Since Florida launched its experiment with concealed-carry in October 1987, 23 states have enacted similar laws, with positive results.
FWIW, I found your comment on my thread because I came back to it by accident while looking for current NRA strategies, i.e. expanding concealed carry and the castle doctrine in other states.