The US Census Bureau just released its population estimates for 2018. As has been the case in previous years, the counties that added the most people (largest numeric growth) are all located in the south and west. Texas holds 4 out of the top 10 spots.
Here is a Tweetstorm by Jed Kolko, the chief economist of Indeed, with a couple of graphs summarizing the findings (click through to see the full thread):
Despite the narrative that people are returning to cities and urban centers, the data is pretty clear: the flow of domestic migration within the US is largely from dense urban counties to more suburban — and affordable — ones. Big cities are expensive.