A trove of paperwork launched this week by the F.B.I. reveal particulars about an assassination menace towards Queen Elizabeth II earlier than a visit that she and her husband made to the United States in 1983, in addition to different safety issues linked to the Irish Republican Army.

The paperwork have been revealed on the F.B.I.’s web site after a request underneath the Freedom of Information Act. The queen, who was Britain’s longest-reigning monarch, died in September.

The plot to kill the queen was shared with a San Francisco Police Department officer in early February 1983, weeks earlier than she and Prince Philip, the Duke of Edinburgh, have been scheduled to go to the United States, the documents show. Specific names and different particulars are redacted from the report.

The unidentified officer mentioned he had obtained a cellphone name on Feb. 4, 1983, from a person who claimed that his daughter had been killed in Northern Ireland by a rubber bullet. The officer frequented an Irish pub known as the Dovre Club, which the F.B.I. described as a gathering place for sympathizers of the Irish Republican Army.

The 1983 go to, like among the queen’s different journeys to the United States, occurred throughout the 30-year sectarian conflict in Northern Ireland often known as the Troubles. Some 3,600 folks have been killed throughout that interval, when Britain deployed its navy to the Protestant enclave to confront teams, together with the I.R.A., that wished to reunite Northern Ireland with the remainder of Ireland.

The man on the cellphone name shared plans to hurt the queen by both “dropping some object off the Golden Gate Bridge onto the royal yacht Britannia” when it sailed beneath or trying to kill her throughout a go to to Yosemite National Park, the paperwork mentioned. Specific particulars about how both plot would have been completed weren’t supplied.

Officials famous that the Secret Service had supposed to shut the walkways on the Golden Gate Bridge when the yacht was close by. Though it’s unclear if any arrests have been made, the paperwork observe that the monarch’s go to was accomplished “without incident.”

The F.B.I. didn’t instantly reply to a request for touch upon Friday morning.

The New York Times covered the queen’s tour of the West Coast on the time, describing it as a glowing affair punctuated by a go to to President Ronald Reagan’s ranch in California. It was reported that inclement climate had forced the royal couple to fly reasonably than sail into the Bay Area, though they participated in a dockside send-off celebration.

The queen said her time on the West Coast was “a wonderful and enjoyable journey.”

Security issues about among the queen’s different visits to the United States have been additionally outlined within the paperwork. Before her journey to Kentucky in 1989, the F.B.I. mentioned it was unaware of any particular threats towards the monarch, however famous “the possibility of threats against the British monarchy is everpresent from the Irish Republican Army.”

During one other journey, in 1991, the queen attended a Baltimore Orioles sport with President George Bush. F.B.I. officers took observe of a letter revealed in a Philadelphia Irish newspaper earlier than the journey.

Officials mentioned Irish teams have been planning to protest the queen on the baseball sport and that an Irish group had reserved a big bloc of tickets.

According to The Times, that night time the queen and others sat within the glass-fronted field reserved for the crew’s proprietor. After greeting the gamers and earlier than taking her seat, the queen waved on the crowd, which burst into cheers and applause.