## Facts

- Williamson organized and operated a gas company that competed in the natural gas business.
- Columbia Gas & Electric Corp. (Columbia) acquired control of Williamson’s company.
- Williamson alleged that, after obtaining control, Columbia managed the company to serve Columbia’s interests rather than the company’s, with the purpose and effect of destroying the business.
- Williamson claimed this conduct caused severe financial injury and forced him into bankruptcy.
- Williamson (through his bankruptcy representative) filed two federal antitrust actions in the District of Delaware against Columbia based on the same alleged course of conduct and the same claimed injuries.
- The first action was filed earlier and named Columbia along with additional defendants.
- A second action was filed later against Columbia alone, again seeking damages for the same injuries arising from the same asserted antitrust wrongdoing.
- The second action reached final resolution first and was dismissed on the merits.
- Relying on that merits dismissal, Columbia moved for summary judgment in the first, earlier-filed action on the ground that the prior judgment precluded further litigation.
- The district court granted summary judgment for Columbia in the first action, and Williamson appealed, arguing the two suits were not substantially identical.

## Issues

1. Does a final judgment on the merits in a later-filed antitrust action bar an earlier-filed, still-pending antitrust action between the same plaintiff and defendant when both actions seek recovery for the same injuries and are substantially identical?

## Decision

- The Third Circuit affirmed the summary judgment for Columbia in the first action.
- The court held that the final judgment on the merits in the second action precluded continuing the first action against Columbia because both suits were substantially identical and sought damages for the same alleged injuries.
- The court rejected the argument that differences in how the claims were framed, or the presence of additional defendants in the first action, allowed Williamson to proceed against Columbia despite the prior merits judgment.

## Legal Principles

- A final judgment on the merits precludes later litigation of the same cause of action between the same parties.
- For claim-preclusion purposes, actions are treated as the same cause of action when they are substantially identical—i.e., they rest on the same basic events and seek redress for the same injuries.
- When a defendant is common to both actions, the addition of other defendants in one suit does not avoid preclusion as to the common defendant if the claim against that defendant is essentially the same.
- A plaintiff may not maintain multiple actions seeking the same damages for the same alleged antitrust harm by restating the claim in a second complaint and then attempting to continue the first after a final merits judgment issues in the second.

## Conclusion

The Third Circuit held that Williamson could not continue his earlier-filed antitrust suit against Columbia after the later-filed suit against Columbia ended in a final judgment on the merits, because the two actions were substantially identical and sought recovery for the same alleged injuries arising from the same conduct.


Williamson v. Columbia Gas & Electric Corp., 186 F.2d 464 (3d Cir. 1951)