Uhhh, I may be wrong, but I've always thought the oils in ground cornmeal would turn rancid after being stored for a long while (assuming the bugs didn't ruin it first), unless you oven can the cornmeal in jars with lids, or vacuum sealed it in #10 cans or mylar bags with oxygen absorbers.
I would think for really long term storage (i.e. years) it would be preferable to vacuum seal or mylar bag whole corn and then grind it as needed for cornmeal. Keeping it as whole corn until needed makes it less likely the oil in the kernel will turn rancid.
Someone with more experience with storing corn/cornmeal can maybe confirm this or explain it better.
Agreed. Buy 50lb bags of popcorn. The last one was about $25. I store mine in 1/2 gallon glass jars that are vacuum sealed. It can be ground and makes good cornbread.