919 (Mich. 1887),[1] was a case that has played an important role in the evolution of American contract law involving the doctrine of mutual mistake.
The substance of the appellate decision, which was rendered by the Michigan Supreme Court after the defendant and appellants set out 25 assignments of error, involves a transaction between Hiram Walker et al., importers and breeders of polled Angus cattle (and grocers and distillers), and Theodore Sherwood, a farmer and banker from Plymouth, Michigan.
On May 5, 1886, Sherwood called upon the Walkers at their farm and adjacent pasture land in Walkerville, Ontario, but did not find a cow that suited him.
In turn, Sherwood brought suit in the Justice Court of Plymouth, Michigan, and obtained a writ of replevin for possession of the cow.
[11] If it is assumed that the trial court proceeded in accordance with the appellate decision, the second jury's verdict indicates a factual finding that any mistake concerning the cow's fertility was mutual.