- make sure there is some type of water on your property, shallow pond would be ok
- build different biotopes: leave some pasture area, plant patches of different bushes.
- plant some fruit trees and few solitair trees (depending on your geography it might be oak, linden or whatever. Ask at your garden center)
- build/buy and place different insect hotels in various parts of property
- when mowing the grass always leave some part (say 1/3) intact
- I am not familiar with situation in US, but in Europe you can find mixes of wild species seedings for given geography. You can use those to speed up biodiversity growth in the area.
For more inspiration you can listen to the Tim Ferriss podcast with Jason Fried (CEO of Basecamp)[1] somwhere at the end of the pocast he is talking his hobby of restoring prairie.
It's in the Irish midlands and I'll be living there as well in a 210ish year old cottage, which will certainly be a shift. For dealing with the grass I had some idea that sheep might be friendlier than mowing, but sheep also tend to destroy everything in their path and stop seedlings.
I was thinking I might try to grow food in this model - http://www.themarketgardener.com/book/ - but that would be on less than half the space.
Clearly I have lots of research to do.
"Restoring the ancient Caledonian Forest Alan Watson Featherstone TEDxFindhorn"
https://www.nrcs.usda.gov/Internet/FSE_PLANTMATERIALS/public...
https://cpw.state.co.us/Documents/CNAP/RevegetationGuide.pdf
Edit: fixed the links
This is a great book wrote for the british isles, the design principles it covers would be very useful in a rewilding project https://www.amazon.co.uk/Earth-Care-Manual-Permaculture-Temp...
And this is a great book if you want to farm sustainably https://www.amazon.co.uk/Growing-Green-Organic-Techniques-Su...
Google for land trusts in your area.
Given that there's a thatched cottage from ~1800 on the land it's already subject to a fair number of restrictions, incidentally, though those are all related to heritage.
That may not be a bad thing, of course. But definitely something to keep in consideration.