Lawyers for New York snarled that their learned colleagues from across the water were blind to history. The New Jersey side shot back that New York was living up to its name as the Empire State, seeking to expand in every direction.

The opening arguments in an unusual lawsuit over who owns Ellis Island started today in a paneled meeting room of the Supreme Court of the United States, the first time in the annals of the court building that an actual trial has been conducted under its roof.

This case is unique in the fact that it is here in this court," said Paul R. Verkuil, the law professor appointed by the Supreme Court to hear the case. "It is unique in the sense that this island is one of a kind, one that has been argued about for a long time."

Bile oozed across the lectern as each side mustered 200 years of accumulated skirmishing for the trial, expected to last a month and to include a field trip to the famous rock itself, with dueling experts as guides. New Jersey, which filed the lawsuit in 1993, is essentially treating the case as a boundary dispute, while New York seeks to establish that the case is a question of property, one it should win because it has long controlled all activity on the island.