Not Ha but Have, duh
Ok, what state are you in? Laws vary. First, see if the state allows non-judicial condemnation. Often a panel of homeowners will hear the case and make an award. The state will present an ‘estimate of value ‘ which may or may not be based on an appraiser. You will need an appraisal to see if the value offered is reasonable. There will be the value of the taking as well as damages to the remainder ( road proximity, impact and n resale value). If the state is judicial, you may need an attorney.
Go on line to the Appraisal Institute and search for a designated appraiser who is knowledgeable about eminent domain, pay for a consultation.
Good luck
Don’t take first offer most of the time the low ball hold out.
Until they are about to serve you condemnation papers the strike the best deal.
Getting lawyers involved well just make the lawyers rich.
All property could be subject to condemnation.
If there was not an active offer or proceeding at the time of sale. I wouldn’t think disclosure was necessary.