Summary of Caterpillar v. Lewis 519 U S. 61 
Relevant Facts: Lewis, a Kentucky resident, commenced this civil action in Kentucky state court after sustaining personal injuries while operating a bulldozer. Asserting state-law claims, Lewis named as defendants both the manufacturer of the bulldozer–petitioner Caterpillar Inc., a Delaware corporation with its principal place of business in Illinois–and the company that serviced the bulldozer–Whayne Supply Company, a Kentucky corporation with its principal place of business in Kentucky. Liberty Mutual, a MA corporation, intervened later as an additional Pl, asserting subrogation claims against Whayne and Caterpillar. Lewis entered into a settlement agreement w/ Whayne, which allowed Whayne to be dismissed as a Df. With 1 day to spare the statutory req. Caterpillar filed a notice of removal to Fed D. CT in Kentucky, based on complete diversity after Whayne exited the case post-settlement.
Legal Issue(s): Whether a district court’s error in failing to remand a case improperly removed is fatal to the ensuing adjudication if federal jurisdictional requirements are met at the time judgment is entered?
Court’s Holding: No
Procedure: Lewis objected to removal and moved to remand to state ct. (Liberty had not settled its subrogation w/ Whanye yet). D Ct denied that motion without addressing argument. 3 yrs later Liberty and Whayne settled. Jury trial followed, verdict for Caterpillar. Sixth Circuit vacated the judgment, concluding that, absent complete diversity at the time of removal, the District Court lacked subject- matter jurisdiction. 6th erred in resting its decision on the absence of subject matter jurisdiction. Reversed and remanded.
Law or Rule(s): Motion for remand for defects in removal must be made within 30 days. District court orders remanding cases to state courts are not reviewable on appeal or otherwise. Despite a denial of a motion to remand if a jurisdictional defect remains uncured, the judgment must be vacated.
Court Rationale: At the time of trial there was complete diversity and federal subject matter jurisdiction. Caterpillar failed to meet the 1441 req that the case be fit for federal adjudication at the time the removal petition is filed. Lewis timely filed motion for remand and did all that was req to preserve his objection to removal. No jurisdictional defect lingered through judgment in the District Court. The procedural requirements for removal remain enforceable by the federal trial court judges to whom those requirements are directly addressed. The well advised Df will foresee the likely outcome of an unwarranted removal = a swift and nonreviewable remand order attended by the displeasure of a district court whose authority has been improperly invoked.
Plaintiff’s Argument: Removal of the case when diversity was incomplete is a jurisdictional defect therefore the court lack subject matter jurisdiction. Adherence to the rules Congress prescribed for removal would have kept the case in state court.
Defendant’s Argument: At the time of trial and judgment complete diversity existed because of the change in parties, ie. Whayne’s absence, which cured the procedural misstep.