

When was this? This is absolutely not the norm today. On the east coast We typically start at 1.2 to 1.5x the appraised value, and go up significantly more based on how much legal fight and public outrage is created.
I’ve been involved twice in my career (for around 140 properties total), with the backing of the Federal government, the FHWA in both cases in my experience, the land is the property of the state as soon as the papers are filled (referred to as ‘quicktake’, not something a state government can do without federal authority), but the legal proceedings for the total compensation can go on for 10+ years if you have the money to fight it. Total comp is often 5-20x what the property is worth plus all of the legal fees.
The only way I can possibly think of your grand parents farm being taken without them being more than well compensated, is if it happened under Eisenhower.

Capitalism is fine.
Unchecked wealth that controls the government, doesn’t pay taxes, and bribes public officials to pick winners and losers is not.
Anyone who thinks that the US is a shining example of “capitalism” is a fucking imbecile.