This was an action originally commenced before a justice of the peace, and taken by appeal to the Circuit Court, where the plaintiff had judgment for fifty dollars and costs.
The evidence showed that the parties had traded horses; that, a month or two after the trade, the horse which plaintiff got, died, and that he was unsound when the trade took place. There was no evidence of any false representations, or warranty on the part of the defendant in making the trade. After *143the death of the horse the plaintiff informed the defendant of the fact, and alleged that he was diseased at the time of the trade, whereupon the defendant promised to pay the plaintiff fifty dollars, or let him have a fifty-dollar horse, if he would not sue.
This action was brought to recover the fifty dollars. On the trial, the Circuit Court instructed the jury as follows:
“ If the jury believe from the evidence that there was a horse-trade between Watkins and McKinley, out of which a difficulty had .grown, and that Watkins was threatening to sue McKinley, and not deceiving him by any misrepresentations, and that McKinley, rather than be sued, promised Watkins .that he would pay him fifty dollars, then said promise is binding; and this regardless of the question as to whether McKinley would or would not have been liable in the suit which Watkins was threatening to bring against him.”
The only question in the case is as to the propriety of this instruction, and in one point of view it is clearly erroneous. It assumes that the defendant would be bound by his promise, whether assentra to by the plaintiff or not. Unless the plaintiff were bound on his part not to do the act which formed the consideration of the promise of the defendant, the agreement was void for want of mutuality. The promise of defendant to pay fifty dollars if plaintiff would not sue him was incomplete till accepted by the plaintiff. Chitty on Contracts, 13.
A mere offer, not assented to, constitutes no contract; for there must be not only a proposal, but an acceptance thereof. Story on Contracts, § 377, 378.
The instruction in other respects is very nearly, if not quite, correct. It assumes that, in order to support the promise, there must have been a horse-trade between the parties, out of which a difficulty had arisen, and that the plaintiff was threatening to sue the defendant, and not deceiving him by any misrepresentations. If by this is to be understood, that the plaintiff must in good faith have supposed that he had a good cause of action against the defendant, growing out of the horse-trade, the instruction is strictly proper. It is immaterial whether the plaintiff could have recovered in such action or not. If he honestly *144supposed that he had a good cause of action, the compromise of such right was a sufficient consideration to uphold a contract fairly entered into between the parties, irrespective of the question as to mSo was in the right. It has often been decided that the compromise of a doubtful right is a sufficient consideration for a promise; and it is immaterial on whose side the right ultimately turns out to be, as it must always be on one side or the other, because there can be but one good right to the same thing. Taylor v. Patrick, 1 Bibb, 168; Russell v. Cook, 3 Hill, 504; Moore v. Fitzwater, 2 Rand. 442; O’Keson v. Barclay, 2 Penn. Rep. 531.
If the plaintiff was threatening to sue on a claim which he knew was wholly unfounded, and which he was setting up as a mere pretence to extort money from the defendant, a contract founded on a promise not to sue in such a case would be utterly void. In order to support the promise there must be such a claim as to lay a reasonable ground for the defendant’s making the promise, and then it is immaterial on which side the right may ultimately prove to be. Edwards v. Baugh, 11 Mees. & Wels. Rep. 641; Perkins v. Gay, 3 Serg. & Rawle, 331.
The judgment of the Circuit Court is reversed, and the cause remanded.
Judgment reversed.
Treat, C. J., dissented.