Rohit Kumar did the world a favor by putting .sql files of the world's countries, states and 47,000 cities in his github repo: https://github.com/hiiamrohit/Countries-States-Cities-database If you have a geo component to your Web application, this saves you dozens and dozens of hours of work, and it's in mySQL format!
Except that there are no cities listed for the USA states of New Hampshire, New Jersey, New Mexico, New York, North Carolina, North Dakota, Rhode Island, South Carolina, South Dakota and West Virginia.
I have researched all of the cities in these states and compiled all of the cities in these states into this .sql file.