"It is Mr. Mackay's ambition to eclipse all others. The homes of the Vanderbilts, Astors, Whitneys and Goulds are to be nothing in comparison to the splendid place planned by Mr. Mackay."

So wrote Peter Ross in his 1902 book A History of Long Island. While Harbor Hill, Clarence Mackay's dream house in Roslyn, might not have eclipsed those mansions, it was the most celebrated house of its day and its occupants were celebrities rarely absent from the pages of the New York newspapers.

The history of Harbor Hill is the story of Roslyn itself, and even though the mansion was slowly demolished, meeting its final end in the 1950s, people still talk about the place. Clarence Mackay was the subject of a recent meeting of the Roslyn Landmark Society and now, W.W. Norton has published Harbor Hill: Portrait Of A House, a book written by Richard Guy Wilson, a professor at the University of Virginia and one complemented with numerous photographs of the mansion's interior and exterior.

Clarence Mackay was the son of John Mackay, an Irish immigrant who moved out West and made his fortune in banking, silver mining, and the newly lucrative cable business. John Mackay is still remembered fondly in the state of Nevada and a statue of him sits on the campus of the University of Nevada.

Clarence, meanwhile, moved back east and settled in New York. During the Gilded Age, America's economic prowess reached and soon surpassed those of Great Britain, Germany and other European powers. Americans were aware of their standing as one of the world's leading nations and one way to flaunt that wealth, apparently, was for the top echelon of society to build their own mansions, ones that would rival the great estates of Europe.

That certainly was the intention of Clarence Mackay---and most especially his wife, Katherine Duer Mackay. Harbor Hill was in fact commissioned by Katherine, a young woman who was born into New York's high society and who even after her marriage to the wealth Mackay, remained someone of great ambition and striving. Katherine was an attractive and photogenic woman who was often photographed while wearing a princess crown.

The architect for Harbor Hill was the already world-famous Stanford White. Set on 648 acres in Roslyn, Harbor Hill was home to numerous buildings and gardens. It soon boasted one of the finest art collections in the world, including a handsome array of armor works from throughout the centuries. As the book jacket explains, the estate was a mirror of the times: "Old versus new wealth; religious differences and the commissioning of churches; the acquisition of a fabulous art collection; love matches and tempestuous separations; and the many people, from the architects, builders, and workers to the servants and staff who ran the house and gardens."

Part of Harbor Hill's charm was not only the impressive array of buildings, but also the staff, which included cooks, chefs, stablemen, chauffeurs, washers, auto mechanics, dairymen, and herdsmen. In fact, it was typical of the people who populated the pre-Pearl Harbor Long Island: The old (or new) moneyed families living on large estates staffed and managed by blue collar workers. And those workers, according to Wilson, were generally content with their place. "As employers, Katherine and Clarence inadvertently outshone the European aristocrats they aspired to emulate," Wilson writes. "The long tenure of many Harbor Hill workers can be attributed...to the Mackays' democratic...awareness that employees will stay only if treated to a measure of comfort and respect."

At the same time, Harbor Hill, at least at first, was unpopular with Roslyn residents. The estate had previously been home to a picnic spot favored by the locals. But the energetic Mrs. Mackay eventually won over the residents. Katherine initiated and supervised much renovation work in Roslyn, including those on both Trinity Church and St. Mary's Church. She also held charity bazaars, church fairs, and annual parties for Roslyn children on the Harbor Hill grounds.

Katherine even served on the Roslyn School Board. A staple on the society pages, Katherine was also the author of a play and novella, both of which hinted that there was some unhappiness in the author's own life.

And indeed, Katherine separated and then divorced her husband in 1914, settled down in Paris with a physician friend. This led the gossip pages to conclude that the Mackay marriage was one of convenience all along.

After the divorce, Harbor Hill was home to much sadness, but it still remained a famous destination. Such notables as the Prince of Wales and Charles Lindbergh were welcomed as guests and Clarence was heavily involved in the Allies' war effort during World War I. By the 1920s however, Mackay's cable firm, Postal Telegraph and Commercial Cable, was losing its share of the market to Western Union. In 1928, he merged Commercial Cable with Sothenes Behn, but the 1929 stock market crash hit Mackay and Harbor Hill's days were numbered.

Clarence died in 1938 and the next year, Harbor Hill, encumbered by huge debts, went on the market. The artwork and armor collections were put up for auction and the subdivision rush began in 1941 when 28 acres were purchased for the development of "American Colonial style" houses. In 1947, the great mansion was being torn down, a process that was complete by 1955. By then, with all of Long Island being reconfigured for good, 368 acres were subdivided into more than 400 sites for residential housing. There remains a street named Mackay Way on the site, a remnant of a lost age in Long Island history.