The Religious Landscape of the Midwest

I was amazed by the billboards and symbols of religion along the roadways of the Midwest. The other day while driving in Ohio we came across a massive cross on the side of the road. It was like two stories high! It just stood alone on the side of the road. (see photo I took while driving)
        Some of the billboards had Scripture verses, one had the entire list of the ten commandments (I though someone might crash their car if they read all of them while driving!), one said "America, bless God!" Another said, "Adoption, not Abortion."
       When I drive to the Northeast of the U.S. I don't see too many billboards and symbols to secular liberalism, even though it is widespread here. I wonder why Christians dot the landscape with religious symbols all over the midwest but liberals don't do the same in the northeast.
       Just pondering!