Traditionally "sold" as an expression of disbelief. I mean, to say that something is not to be believed, you imply that anyone who believes it is incredibly gullible by offering to sell them the Brooklyn Bridge:

"...and if you believe that, I've got a bridge I'd like to sell you..."

If you were to absolutely quantify why the Brooklyn Bridge makes all the lists as "a modern wonder of the world", you’d be hard-pressed to call it a truly modern wonder. In today’s world of well-known material characteristics and computer-aided engineering, exotic and precisely mixed steels have expanded bridges well beyond the scale of the Brooklyn. Stone is simply not used to build bridges anymore, and bulldozers have replaced the slower teams of men with pickaxes. Computer modeling would ensure that a bridge on Brooklyn’s scale could stand long before the first caisson was built, and as for organizing such a massive effort without computerized spreadsheets, no one person would ever be able to do it.

...Except that a hundred years before computers, decades before internal combustion, one man did do it, and the results still stand today. The brilliance of the Brooklyn Bridge lies in that same inspiring quality which allowed the pyramids to be built. Both monuments—both wonders—are testaments to a man’s ability to rise above the supposed limits of the day, to motivate staggering numbers of other men in a project that seems preposterous on paper (or papyrus). The Brooklyn Bridge is really the first of the modern wonders, the granddaddy of them all, and the first tangible evidence that the next hundred and thirty years would be full of sweeping changes.

At the beginning of 1869, Thomas Edison was soon to set up shop in Menlo Park and alter the face of the world with his inventions. The Civil War was over, and the country was still dealing with the massive losses that had occurred as battlefield technology developed more quickly than the tactics of the day. Everything that happened in the years leading up to the twentieth century was just like that: technology had advanced so quickly in the first stirrings of the Industrial Revolution that nobody was certain yet what new creations were possible. Engineers who didn’t lose their heads in the dizzying expansion, however, could be relied upon to make sound guesses using tried-and true principles, and design (based on those guesses) impressive examples of man’s newfound powers.

The elder Roebling, John, designed the Brooklyn Bridge with a safety factor of six. From an engineering perspective, this is a conservative and perfectly reasonable thing to do. In the modern world, safety factors are more and more often between one and two, as materials are better known and the mechanics of a design are more apt to be similar to those of an existing design. At the time, however, one bridge in four was failing because engineers were being too bold with assumptions about material strengths, scalability, and technology. John Roebling’s commitment to the bridge’s safety and permanence is similar to the obsessive perfection with which the ancient Egyptians sighted the square corners of their pyramids.

Of course, nobody can know if the pharaohs themselves were concerned with the details of the pyramids to the degree that the Roeblings were involved in the Brooklyn Bridge. The fact that the pharaohs would eventually become a permanent part of their engineering masterpieces is the only evidence that they could have possibly been as committed as their modern counterparts. Even a man revered as a god would have a hard time living up to the standards that both Roeblings set for themselves. Perhaps their stoicism, or heroism, or perfectionism, or whatever you choose to call it, is part of what makes the bridge a wonder: it is amazing that two men, father and son, bent steel and human will to this project with such fanatical dedication almost irrespective of the other’s accomplishment.

John was indeed as eager to see the bridge built as his son, and as demanding about the perfect execution of such a grand work that only death (and that, most grudgingly) could stop his work on it. He drew the plans up in three months. "Drew"--by hand, on paper, including, according to McCullough, "surveys... soundings... cost estimates, and a written proposal, nearly fourteen thousand words in all." Even today, for an engineer with modern word- and image-processing software, and access to limitless information, drawing up complete plans for a civil engineering project on that scale would be simply absurd, given any time limit--one man could not handle it today. Even in the accident that led to his death, the elder Roebling’s sense of duty was crystal perfect; historian David McCullough reminds us that "he gave no sign of his excruciating pain. He went right on shouting directions until he toppled over, unable to stand any longer." The anecdote is typical of John Roebling, but can also be taken as a metaphor for his life, as well as the life and work of his son.

The younger Roebling, upon taking over the project, was, like his father, a classic perfectionist and micromanager. Certain of his father’s vision as if it were his own, Washington nevertheless checked every last detail himself, or had a trusted associate check for him. He strove to realize his father’s ideal to a degree that was unhealthy for him, and he was eventually rendered invalid by the long-term effects of working double and triple shifts in hazardous working environments checking on the project’s minutiae. The story of the Brooklyn Bridge is also the story of how Washington Roebling poured everything he had into it, overcoming obstacles like the deception and outright sabotage of a Mr. Haigh, whose inclusion of flawed steel would have destroyed a modern (safety factor of ~2) bridge. Indeed, Colonel Roebling poured his life into the bridge, and didn’t regret anything except the fact that he was less and less able to personally oversee the construction. Like his father, he would have been content to shout directions until he could stand no longer. Fortunately, he was alive to see the completion of the bridge, and participate in the opening ceremonies. It isn’t really any wonder that Americans had difficulty separating the two Roeblings in their minds. Father and son were both a little insane about the bridge, both fervent and faithful managers who placed a high value on integrity and leadership by example, both the sort of men who America always takes as heroes.

The Brooklyn Bridge is a wonder for three reasons. First, it is a management and leadership feat equal to the pyramids and surpassing many of the modern projects that dwarf it in physical scale. Second, it broke new ground at a critical moment in history, showing the world the true scale on which modern engineering miracles could be performed, if there were people willing to make it happen. Finally, the Brooklyn Bridge inherited personality from her designers, the Roeblings, and became a monument to their passion for magnificence: anything less than the Brooklyn Bridge wouldn’t have been a fitting testimony to the greatness of the engineering minds of the day.

The construction of the Brooklyn Bridge was, in the end, made possible via a bribe of around $60,000 payable to the aldermen of New York City (meaning, at that time, Manhattan). The money was provided by William C. Kingsley, the richest contractor in the City of Brooklyn.

Additionally, Kingsley bought half of the Bridge Company's private stock and gifted it to William Magear "Boss" Tweed (who was the head of the Public Works department at the time) in order to get final approval. The inevitable value of the stock itself was garnished by the fact that Tweed could now hand out bridge work to his own people and let the kickbacks roll in.

Kingsley was gambling that these generous bribes would allay any fears Tweed or the aldermen might have about easy access to Brooklyn siphoning away wealthy home buyers from Tweed's Upper East Side real estate developments.

Information distilled from Gotham: A History of New York City to 1898 by Edwin G. Burrows and Mike Wallace (no, not that Mike Wallace.)
Brooklyn Bridge

apologetic lights soft, moth wings beat glass,
laced, bridgeless, over the teeth of the skyline.
hands swollen from salt (and thinking of boys)
hold the peeling-paint rail to steady the eyes.
as they watch, dark eyes, drink up reflections
of dusty halos of street lamps off black water.

your name passes soundless by my lips.
the word is the same shape as your kiss.
your eyelashes are too long for a boy.
they brushed my cheek when you blinked.
your hair would sell for a good price
it is as heavy as gold.

still, I am at the river, dreaming.
the wind that hints of sea water wakes me.
the lights hang on the Brooklyn Bridge
glowing like my thighs’ treasure
naming the shape of the invisible bride

words fail between us.
so many are known,
that no two words,
not love, not lust,
can name the same dream.
