How long does USPS take to delever mail in the same state?

I have found from experience it is possible to receive mail the next day even from a few states away. The USPS now uses Fedex to move some of their first class mail, so it seems they are able to move more of their mail quickly across the US.

I suppose if you lived in a very small town, a long distance from any major town, and sent a letter to another very small town that was also a long distance from any major town, it might take more than a day on average, but I am always impressed how fast the US mail is compared to 10-20 years ago.

Of course Christmas season when the post office has the big rush to mail lots of things your letters and packages might be delayed more than usual as well