## Facts

- Slaughter sold slaves in Mississippi, receiving two promissory notes executed in Natchez in December 1836 by John W. Brown, payable at a Natchez bank.
- The notes were endorsed by R. M. Roberts, Moses Groves, and others.
- The notes were dishonored and protested for nonpayment.
- Slaughter sued the endorsers in federal circuit court in Louisiana to recover on the notes.
- The endorsers asserted the notes were void because the slaves had been brought into Mississippi for sale contrary to a Mississippi constitutional provision authorizing the legislature to prevent such importation.
- Mississippi did not enact implementing legislation for that constitutional provision until 1837, after the December 1836 transaction.

## Issues

1. Whether Mississippi’s constitutional clause concerning importation of slaves for sale was self-executing so as to invalidate contracts made before any implementing statute.
2. If the clause were operative without legislation, whether it would impermissibly burden interstate commerce under the Commerce Clause.

## Decision

- The Supreme Court affirmed judgment for Slaughter.
- The Court held the Mississippi constitutional clause was not self-executing and required legislative implementation to have operative legal effect.
- Because Mississippi’s implementing statute post-dated the transaction, the notes were not void on the asserted illegality theory.
- The Court resolved the case on the state-law ground and did not render a controlling determination on the Commerce Clause question, despite extensive separate opinions.

## Legal Principles

- A state constitutional provision that authorizes or contemplates prohibition of a practice may require implementing legislation before courts may treat it as legally operative against private contracts.
- Absent effective state legislation in force at the time of contracting, a defense of illegality based on a later-enacted prohibition generally fails.
- When a case can be decided on an adequate state-law ground, the Court may avoid deciding a federal constitutional question.

## Conclusion

The Court enforced promissory notes given for the purchase of slaves because Mississippi’s constitutional authorization to restrict importation for sale required implementing legislation, and no such law existed when the notes were executed; the Court therefore affirmed without issuing a binding Commerce Clause ruling.


Groves v. Slaughter, 40 U.S. (15 Pet.) 449 (1841)