Osborne v. McMasters, 40 Minn. 103, 41 N.W. 543 (Minn. 1889)
Osborne v. McMasters is a foundational negligence case that crystallizes the doctrine commonly called negligence per se: when the legislature prescribes a specific standard of conduct for safety, a breach of that statutory duty constitutes negligence as a matter of law if it causes the type of harm the statute was meant to prevent to a member of the protected class.
Does the violation of a statute that imposes a specific safety duty create negligence per se in a civil action when the violation proximately causes the type of harm the statute was designed to prevent to a person within the protected class?
Where a statute or ordinance imposes a specific duty for the protection or benefit of others, a violation of that duty is negligence as a matter of law (negligence per se). If the plaintiff is within the class the statute was intended to protect and suffers the type of harm the statute was designed to prevent, and if the statutory violation proximately causes that harm, the defendant is liable in negligence, subject to defenses such as contributory negligence and considerations of causation. The fact that the statute provides a criminal penalty does not preclude its use to establish civil negligence.
Yes. The defendant's failure to label the poison as required by statute constituted negligence per se, and because the jury could find that this violation proximately caused the decedent's death, the plaintiff could recover. The judgment for the plaintiff was affirmed.
Osborne v. McMasters anchors the negligence per se doctrine in American tort law. It teaches that statutes can supply the duty and standard of care, transforming breach into negligence as a matter of law when the plaintiff and harm fit the statute's protective purpose. The case is central for analyzing how criminal or regulatory provisions intersect with tort liability, and it highlights the necessary elements students must test for: protected class, protected interest, kind of harm, and causal nexus. It also illustrates that statutory violation does not automatically establish liability; causation and defenses like contributory negligence remain live issues for the factfinder.