The range of potential fixes could be from epoxy injecting the cracks, which would cost roughly a few thousand dollars, to soil or foundation stabilization, which could cost a few tens of thousands of dollars. 

Worst case, you would want to slope the soil a few feet from the foundation and maybe add a french drain.  

if you have no gutters or downspouts taking the roof water away from the foundation its going to puddle .. and of course depends on the soils etc.. 

When was the house originally constructed and in what type of soil (embankment or natural soil)?

You can get someone to come out and do this, if you find them you probably need to do soil testing.

It can be leased out to farmers depending on the soil quality.

Nefarious folks may try dumping oil, chemicals, etc. on your land and contaminate the soil.

It is a 90 year old Florida house so not sure if the property sank into the wet soil over time and wood has rotted or if they just didn't build crawl spaces in those days. 

Also, you may have a little trouble if you're thinking of replicating your strategy from Appleton here - something you should know about Houston (and several parts of Texas) is that the weather + soil composition often leads to home foundation issues. 

Has it been soil tested?