American Well Works Company v. Layne and Bowler Company
The Court ruled that a business's lawsuit over a competitor's threats and false claims of patent infringement belonged in state court, not federal court, because the harm came from state law protecting businesses from unfair interference, not from the patent laws themselves.
The decision drew a lasting line for how courts decide whether a case 'arises under' federal patent law: what matters is the law that creates the right being sued on, not whether a patent might come up as a side issue or defense.
“A suit arises under the law that creates the cause of action.”
The Court's core test for deciding whether a case belongs in federal court under the patent laws.
How it got here: Filed in state court, the case was removed to federal court, which then dismissed it for lack of jurisdiction; it reached the Supreme Court directly from the district court.
The Case in Depth
What happened
A company that made and sold a pump claimed a rival falsely and maliciously told customers and others that the pump infringed the rival's patent, and threatened to sue anyone who bought or sold it. The pump maker said these threats and statements scared off business, causing $50,000 in real losses plus punitive damages, and sued in state court.
The question before the Court
If a pump maker sued rivals in state court for scaring off its customers with patent-infringement threats, did that lawsuit really belong in federal court as a patent case?
Why it matters
Businesses harmed by a rival's threats or false claims about patents can sue in state court under ordinary business-tort law, without needing to prove anything about the patent itself. This keeps many disputes over unfair competition and business interference out of federal court, even when patents are mentioned, shaping how such cases get filed for generations.
What changes now
The Supreme Court reversed the lower federal court's dismissal, meaning the case should not have been treated as a federal patent matter and belongs in state court under state law. This is a final ruling on the jurisdictional question, though it does not resolve the underlying dispute over the pump maker's claims, which would proceed, if at all, in state court.
What this does not decide
The Court did not decide whether the defendants actually infringed any patent, whether the plaintiff's own patent was valid, or who should ultimately win the underlying business dispute. It decided only which court system had authority to hear the case.
Concurrences and dissents
Dissent — Justice McKenna
“the case involves a direct and substantial controversy under the patent laws”McKenna's brief statement explaining why he would have kept the case in federal court.
Justice McKenna dissented briefly, stating only that he believed the case actually involved a direct and substantial controversy under the patent laws, meaning he would have kept the case in federal court rather than treating it as a state-law matter.
How the Court got there
The legal reasoning, step by step
- The Court explained that whether a suit 'arises under' federal patent law depends entirely on the plaintiff's own complaint, not on defenses the other side might later raise.
- It identified the real basis of the claim as conduct and language that tended to drive customers away from the plaintiff's business and caused it financial harm, regardless of whether that conduct involved threats, false statements, or persuasion.
- The Court reasoned that proving this kind of business-interference claim requires showing only the harmful conduct and its damaging effect, leaving it to the defendant to raise any justification, such as truth of the statements or fair competition, as a separate defense.
- Because a patent might come up only as evidence or as part of a defense, and not as part of what the plaintiff had to prove, the Court held that the presence of a patent question did not convert the claim into one arising under federal patent law.
- The Court concluded that a suit is governed by whatever law actually creates the right being enforced, and since state law creates the right to be free from this kind of business interference, the case belonged in state court and the state's own rules would control the outcome, even the question of what defenses were available.