Employment offers in the US rarely establish contract. Employers often rescind offers that have been accepted by persons for a variety of reasons. Similar for employees.

Sometimes a party that can show they relied on the offer and then suffered money damages after it was rescinded can get some relief in court, but it is rare. Typically these cases are folks who accept an offer, quit their job, and move across the country only to have the offer rescinded or the position is eliminated soon after they start. Most often employees harmed this way lose in court unless there is strong proof that the employer knew they were ending the position before making the offer.