I was in the need for a list of all USA cities and their states. I came across a couple JSON files, but all of them were limited by population. My application needs to know all known cities and states to a reasonable degree in order to aide the user in entering the correct spelling of a city. For that reason, I created this JSON and am sharing it with the community for anyone who needs it. This list includes about 5900+ cities. That beats out the next closest JSON list that I found by nearly 5,000 cities. Enjoy!
As of 2013, the United States has 3,007 counties and 137 county equivalents for a total of 3,144 counties and county equivalents.Cities and towns: According to the U.S. Census Bureau, there are 19,354 “incorporated places” in the United States. — https://www.quora.com/How-many-towns-counties-and-cities-are-in-the-USA
Of those 19k places, only about 3k of them had a population above 10k people in 2015 according to statista. With that, this list of nearly 6k US cities should suffice for your application. If it doesn’t I suggest you consult a maps api, perhaps Google’s.