Bill Clinton was in his first term as president when the peeling hulk of the SS United States was towed up the Delaware River for temporary moorage. The massive ocean liner has now idled in the shadow of the Walt Whitman Bridge for so long that its 12-story stacks are virtually part of Philadelphia's skyline, hardly noticed by the thousands who drive overhead each day.

But the once-grand ship could soon slip away as quietly as it arrived.

Its owner, Star Cruises of Hong Kong, has put the vessel up for sale. Though the United States was the world's fastest, and arguably most luxurious, cruise ship when it made its maiden voyage in 1952, career prospects for middle-age ocean liners aren't particularly bright these days. "Scrap" gets mentioned a lot.

That hasn't stopped a boatload of romantics from sending out a major SOS. An advocacy group called the SS United States Conservancy believes the ship, which arrived here by happenstance in 1996, carries too much history to be discarded so casually. So it's mounting a campaign to save the vessel, starting Wednesday with a free screening of a documentary at the Independence Seaport Museum.

"We keep hearing America doesn't make stuff, but if there is a single thing that represents the golden era when America made the best stuff in world, it's the SS United States," said Steven Ujifusa, a Philadelphian on the conservancy's board.

"What would it say about our country," he added, "to have the SS United States towed to Asia to be scrapped?"

The liner, which was built in Newport News, Va., probably represents the apex of transatlantic travel, as well as America's industrial might.

Its designer, William Francis Gibbs, a Philadelphia native, built it to dislodge the British cruise lines as the rulers of the sea. On its maiden voyage, the United States fulfilled its destiny by capturing the speed record from the Queen Mary, sailing at 36 knots, or 41 m.p.h. - faster than many big ships today.

The United States was a technological advance in other ways, Ujifusa said. Because of its strong construction, the military classified it as a standby troopship, although it was never pressed into service.

The 990-foot-long liner was bigger than the Titanic, and the sight of its sleek prow knifing through the water was said to be breathtaking. Its deluxe midcentury-modern interiors were fitted out without any wood, to make it fireproof.

But being the fastest and safest ocean liner in the world did the ship little good once airlines began flying between the United States and Europe. The ship was pulled out of service in 1969, though it did duty long enough to transport the young Clinton to England in 1968 for his Rhodes Scholarship.

Ujifusa's grandmother had also traveled on the United States, and her stories of its grandeur first ignited his imagination. It wasn't until he visited Philadelphia on a college-scouting trip in 1996 that he spied the real thing.

He remembers driving over the Ben Franklin Bridge and shouting, "There she is!"

Ujifusa has been studying the ship ever since and is writing a book on its history. He also assisted with the documentary Lady in Waiting, which will be screened at 7 p.m. Wednesday at the museum on Penn's Landing.

It's not clear why the ship was dubbed United States, but it became the flagship of the United States Lines, said Susan Gibbs, another member of the conservancy board and the granddaughter of the ship's designer.

Once it was decommissioned, the United States wandered from port to port looking for a home and purpose.

It 1994, it was sent to Turkey for asbestos removal. Although its magnificent interiors were gutted, it was picked up by local businessman Edward A. Cantor, who proposed first turning it into a hotel, then a waterside casino, but merely succeeded in docking it at Pier 82.

It was sold in 2002 to Norwegian Cruise Lines, later acquired by Star Cruises. The company hoped to make it an oceangoing vessel again, but estimates for the retrofit skyrocketed to more than $250 million.

Although the United States' extended stay in Philadelphia was unintentional, Gibbs believes the vessel could have a future in the city as a tourist attraction, much like the Queen Mary in Los Angeles and the aircraft carrier Intrepid in New York. Unlike those two, which retained important parts of their interiors, the United States is a mere shell.

The conservancy argues that the ship would nevertheless add depth to the three maritime attractions now on the Delaware River: the battleship New Jersey from World War II, on the Camden side, and the Spanish-American War cruiser Olympia and the tall ship Moshulu, both docked at Penn's Landing.

The group has already enlisted some big names to support the cause, including yachting enthusiast Walter Cronkite, who died last month, and Philadelphia philanthropist H.F. "Gerry" Lenfest, who has pledged $300,000 to save the ship from destruction.

Dan McSweeney, the conservancy's vice president, said Wednesday's screening was intended to launch a national outreach effort to save the ship. "We'd like to reach a broader audience beyond just Philadelphia."

Contact staff writer Inga Saffron at 215-854-2213 or isaffron@phillynews.com.