Brennan and I talk about the states every day. He has a map of the United States in his playroom and I found a fun song that we both enjoy, rhyming the 50 states. I point to the states as the song is playing and he has learned where about 10 states are. I don't expect him to memorize them, I just think it's a fun addition to our morning routine and certainly won't hurt.
We live in Illinois and cross the river to Missouri quite often to go to St Louis. I show him on the map where we live and where we cross to St Louis. Then when we're driving we talk about the bridges, we have been taking a different one lately due to construction, but we can see the others.
Recently we were at my sisters' apt in St Louis and she happens to have a beautiful view of the river (and The Arch). I had a great opportunity to show Brennan the land in Missouri, the side we were on and the land in Illinois across the river. We also got to see the bridge we drive over from above. It was really neat to be able to explain to him in person (while not driving!) from an aerial view to give him a better idea.
The pictures are not the best, it was my cell phone and it was pretty gloomy that day.