Grits, samp/cornmeal, grist corn groats, hominy, polenta, masa harina are all made of corn that's just processed differently.
Thank the native Americans for introducing it to the Old World where changes in grinding and processing made it a staple in many parts of the world.
You'll find it up and down the east coast, in the middle of the continent, and out on the pacific coast as well.
In the eastern woodlands of North America, if you've eaten Indian pudding, cornmeal mush/mash or samp, Johnnie cakes, dumplings-you've had it. Variations on those dishes and products can be found in the midwest as European settlers settled further away from the shore. Once the European based pioneers meet up with the Mexicans they found tamales, tortillas, and once again hominy waiting for them.
Of course in the southern coastal portion of the states easy enough to find cornbread, grits, griddle cakes, hush puppies and the like.
As for polenta which successfully jumped across the Atlantic and found a new home in the Mediterranean, you can find it boiled with more liquid thus making it more of a porridge or made into a rounded compressed brick to slice and fry or saute. OP, if you had polenta and didn't like maybe try it made another way.