What action should the plaintiff take when suing a defendant from a different state in federal court?

The correct action for a plaintiff suing a defendant from a different state in federal court is typically to consider the legal basis for establishing jurisdiction, specifically diversity jurisdiction if the parties are from different states and the amount in controversy exceeds a statutory threshold.

Filing a supplemental answer generally pertains to providing additional responses to allegations made by the defendant in the context of a case that is already ongoing. It's not a relevant action when initially bringing a lawsuit against a defendant from another state.

In the context of diversity jurisdiction, what the plaintiff actually needs to do is ensure that the federal court has proper jurisdiction over the case, which might involve asserting claims that satisfy the requirements of diversity jurisdiction, rather than opting to file a supplemental answer.

There's also a need to properly establish the venue for the case to ensure it is brought in an appropriate jurisdiction, but that does not require the action of filing a supplemental answer. If the plaintiff cannot establish diversity jurisdiction or any other basis for federal jurisdiction, they may have to explore other options, like remanding the case to state court, rather than seeking to file additional answers.

Thus, the approach to properly manage a case involving parties from different states primarily revolves around ensuring the jurisdictional requirements are met, not filing a supplemental answer