The Ohio River serves as the northern border of both Louisville and Kentucky, given the amount of traffic that passes through here that means there's a lot of bridges (I think 9 currently here in the metro area). I tend to just go wandering with my camera a good deal and down by the river is one of my favorite spots, which is why I have lots of photos of bridges. On the far side of the bridge in the photo is Falls of the Ohio State Park in Indiana which is a fun place in and of itself (it has fossil beds!) and also offers a neat vantage point for photos.
The bridge in the photo is the Fourteenth Street Bridge, an old (for here at least) railroad bridge built back in 1870. One of the other old railroad bridges here in Louisville was turned into a walking bridge after falling into disuse but this one is still in operation.
This second photo was taken standing just past the far right of the first photo and right next to the Fourteenth Street Bridge. McAlpine Locks and Dam are what made the Falls of the Ohio navigable, the canal for that is at the far end of the bridge. The rest of the Ohio River that doesn't pass through the canal goes under the bridge and around, with some of it being released like in this second photo.
Here you can see a train actually crossing the bridge with the skyline of Louisville in the background.