Calder v. Bull

Supreme Court of the United States · 1798 · Constitutional Law

3 U.S. (3 Dall.) 386 (1798)

Updated July 29, 2026

Constitutional LawEx Post Facto Clauseex post factoretrospective lawscriminal lawscivil lawsvested rightsstate legislation

Facts

A Connecticut probate court had originally disapproved the will of Normand Morrison, the grandson, and refused to record it. More than eighteen months passed, so Bull and wife were barred from appealing under a Connecticut statute, and there was no existing state law allowing a new hearing in probate. The Connecticut legislature then passed a resolution setting aside the probate decree and granting a new hearing, after which the will was approved and that approval was affirmed on appeal. Calder and wife, claiming as heir, argued that the legislative resolution was an ex post facto law because it retrospectively upset the prior decree and their asserted right to recover the property.

Issue

Whether the Connecticut legislative resolution granting a new probate hearing and thereby affecting the parties' asserted property rights was an ex post facto law prohibited by Article I, Section 10 of the United States Constitution.

Rule

An ex post facto law, within the meaning of the federal Constitution, is a law that operates retrospectively in criminal or penal matters by making previously innocent conduct criminal, aggravating a crime, increasing the punishment for a crime, or altering the legal rules of evidence to make conviction easier. A merely retrospective law affecting civil rights, property, or remedies is not an ex post facto law within that constitutional prohibition.

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One of 10 multiple-choice questions for this case. Pick an answer to see why.

In Ohio, the legislature enacts a statute making it a misdemeanor to possess a certain herbal stimulant. The statute applies to anyone who possessed the substance during the six months before enactment, even though possession was lawful at that time. Mara Lin is prosecuted based solely on her possession two months before the statute passed.

If Mara challenges the statute under the Ex Post Facto Clause, how should a court rule?

Explanation. The majority opinion defines an ex post facto law, first, as a law that makes an action done before the law was passed, and which was innocent when done, criminal, and punishes that action. This statute fits that category exactly because Mara's past possession was lawful when done, and the new law punishes it after the fact.