We had studied this when I was in grad school. My major was geology and astronomy. The New Madrid was the biggie. Not much structural damage as most of the homes back then were built on the surface, no basements and some log cabin type. So when the shock waves happened things just rolled with the punches so to speak.
Today it would be a real disaster as we have few homes built Florida Style ( slab homes) , a quake would be a real big issue.
We were told at the time that as the erosion of the land filtered down into the Mississippi Delta the added mass would and could precipitate another quake. Hence the push for soil conservation. With Fracking occurring in oil producing areas that as well produces some of the concern. Frequent quakes where none have been for many years are attributed to that.
In Iowa we have two major fault lines. One is up near Cedar Rapids, just south of there and another up in Madrid Iowa at Ledges state part, neither have been active.
A big concern is the Bakken pipeline which runs from the oil fields in South Dakota, across Iowa and to Patoka, Illinois. Crude oil, buried in some places are a concern. Iowa also has many pipelines from gasoline and liquified natural gas. The big concern isn't with a pending Earthquake,but with the freeze and thawing movement of the land itself.
Do I think we will have a quake, sure . When? anyone's guess.
There is a project that Stanford started and USC now has, the quake catcher network :
http://qcn.caltech.edu/It consists of a device, small that you fasten to the floor of your basement for example, but it could be most anywhere, it connects via USB to your home computer and you run a background program 24/7 to monitor any quakes. I used to do that but I was getting way too much back ground noise it wasn't going to be. You could always get involved: