Davis v. Jacoby
Supreme Court of California
34 P.2d 1026 (Cal. 1934)
Mr. Whitehead, desperate for reassurance while depressed and ill, wrote urgently asking his niece Caro Davis and her husband (plaintiffs) to come care for him and his wife until their deaths in exchange for inheriting the Whiteheads' estate, specifically asking for a quick reply; the Davises wrote back promising to come and abandoned their home and business to do so, but Mr. Whitehead committed suicide before they arrived. The Davises nonetheless cared for Mrs. Whitehead until her death per the arrangement, but the Whiteheads' actual wills left the estate to nephews (defendants); the Davises sued for specific performance, and the trial court ruled for the nephews, finding the offer was for a unilateral contract requiring actual performance (not merely a promise) that hadn't occurred before Whitehead's death.
Whether a letter asking family to care for the writer and his wife until each of their deaths in exchange for being willed their assets is an offer to enter into a bilateral contract.