In the case of Beacon Theatres v. Westover (359 U.S. 500 (1958)), the US Supreme Court held that since there is a right to a jury on a legal claim, when a case has both equitable claims and legal claims, the legal claim must be tried first.

• Under the preclusion doctrine, once a claim has been determined that decision will be generally binding on future adjudications.
• Therefore, if the equitable claim were to be tried first, the facts decided in connection with that claim would then be treated as having been established for the purposes of the legal claim. This would mean that the issues of fact which the jury would decide for the legal claim would already have been decided by the judge as part of the equitable claim.
• In this case, the initial suit was brought for an injunction, which is an equity court claim. But the countersuit was for money damages, which is law court claim. In theory, you'd try the original suit before the countersuit, but in this case, the countersuit needed to be tried first so a jury could decide the facts.