Old Missouri land plat books
I posted this for Pipsydog in the Missourian's Locations thread but I thought some others might be interested too. You can see who owned your land in 1930 and who your neighbors were. Click on your county first. It took me awhile to figure out how to look up my specific area. Let me know if you need help.
Here is a link that might be useful: Plat books of Missouri