As I have stated previously, I use Legacy Family Tree software for my family tree. I really like the program. It has some nice features. One of those features is a county verifier. It verifies that a county was in existence at the time of an event.
That being said, most of my family comes from West Virginia which, as you know, was part of Virginia until 1863 when it became an entity of its own. It is hard trying to keep up with which county existed pre-statehood, which county came into existence post-statehood, what year it became a county, etc.
I was getting tired of either Googling this information or looking it up on Wikipedia. So, I found a list of the West Virginia counties, the year they were established and the origin of the county (i.e., what county it was a part of before becoming its own county). I copied it from Wikipedia, cleaned it up and extracted only the pertinent information. This list comes in pretty handy and I refer to it frequently.
I found I was having the same issue with other states, as well. I did the same thing for Virginia, Kentucky, Ohio, Pennsylvania, North Carolina, Maine, Missouri and Illinois. Those are the states most of my family lived in, was born in or died in, at least thus far in my research. I also created a list of the independent cities in Virginia, which includes the year they became independent. I am sure I will eventually have a list for all 50 states, but for now, these will do. I have made the lists available to you. Click on a state for its county list. Note: The Virginia file has two lists, one for counties and the other for independent cities.
I can now make more accurate notes on events when a county is in question. I write in my notes research indicated the event happened in such-and-such a county but it was not in existence at the time of the event. I feel this will help others who look at my genealogical information to get a better picture of what they are looking at.