Black Rat Snake or Black Racer...?

I was out in the yard this morning when I came across these two black snakes. One of them ran off, but the other stuck around for about 15 minutes. I watched it eat a few bugs and slither around. J woke up and looked at it with me, but he wasn't as in to it as I was. It finally slithered off through the leaves and underbrush. I think it is either a black rat snake or a black racer. It was about 2 1/2 feet long and as big around as my thumb. It had a gray belly and a little white (almost) under its throat. It would have been cool if it were an eastern indigo snake, but it doesn't fit the description. Either way, free pest control, and a great view of the local wildlife.
I saw another one a couple of weeks ago, but it was a lot larger. It might have been the mama. Who knows. It was a great thing to watch.