Chronology of border dispute over the Portsmouth Naval Shipyard:

June 12, 1800: The nation’s first naval shipyard is established on Seavey Island in the Piscataqua River.

1820: Maine becomes a state.

1969: Maine enacts an income tax.

1976-77: U.S. Supreme Court approves settlement of Maine-N.H. lobstering dispute with decree establishing the offshore border between the states. The decree did not establish the border inland.

1985 and 1991: Maine court affirms shipyard’s location within Maine.

1991: U.S. Senate rejects legislation sponsored by Sen. Bob Smith, R-N.H., to stop Maine from withholding Maine income tax from pay of New Hampshire residents who work at the shipyard.

1992: New Hampshire shipyard workers sue, arguing they should be exempt from the tax.

1994: New Hampshire lawmakers direct the state’s attorney general to resolve the dispute.

1996: Maine begins garnishing wages of shipyard workers who live in New Hampshire and refuse to pay Maine tax.

1996: Smith asks the federal government to stop collecting the taxes for Maine. The Defense Department says the practice will continue until a court rules otherwise.

1997: New Hampshire Gov. Jeanne Shaheen asks Attorney General Philip McLaughlin to take the dispute to the U.S. Supreme Court.

1997: A Senate committee rejects a bid by New Hampshire’s senators to let workers at the shipyard pay taxes only to the state where they live.

1998: A Maine judge dismisses a class-action lawsuit brought by New Hampshire shipyard workers.

March 6, 2000: New Hampshire asks U.S. Supreme Court to declare the shipyard part of New Hampshire.

April 16, 2001: Court hears oral arguments.

May 29, 2001: Court dismisses New Hampshire’s case, saying it is inconsistent with the state’s position in the 1970s lobstering dispute.