When they set out to make a documentary, those Burns boys are nothing if not thorough.

Together, Ken and Ric produced the 1990 landmark PBS series "The Civil War," which clocked in at 12 hours. Then Ken raised the bar by making "Baseball," an 18-hour project that aired in 1994. Last week, he spent a paltry four hours telling the story of the first ladies of American feminism, Elizabeth Cady Stanton and Susan B. Anthony.

Now, younger brother Ric and co-producer Lisa Ades take a long, long look at a big, big city -- New York.

"New York: A Documentary" is a 10-hour whopper that airs Sunday through Thursday at 9, under the banner of PBS's "The American Experience."

But a year ago, after four years' work, Burns decided he needed two more hours. They will air next spring, chronicling the city from 1931 to 2000 and bringing the total project to 12 hours.

"One thing we discovered was how incredibly rich this material is," said Ades. "This is the most photographed, filmed, written-about, sung-about place. There are so many stories that we didn't have time to treat."

There are many facets about New York that make interesting documentaries in their own right, such as Ken Burns's "Brooklyn Bridge" and "Statue of Liberty" and Ric Burns's "Coney Island." However, Ades said, "we were hoping in creating the story of New York that each episode could connect to a spine that runs through the series." Material they considered peripheral had to be trimmed.

Burns, who also directs "New York," and Ades have worked together for a decade, making "The Way West," "The Donner Party" and "Coney Island," and both are graduates of New York schools. He grew up in Michigan and arrived in New York City in 1976 to begin the first of two degrees he earned at Columbia University (he also has a degree from England's Cambridge University); she hails from Westchester County and graduated from New York University.

In many ways, this documentary from their production company, Steeplechase Films, is a sort of warts-and-all valentine.

"New York is a great case study, the great laboratory to see the rise of American culture and its two impulses, capitalism and democracy," said Burns. "It is a love letter in a way, but we're also both interested in the more complicated and dark side of the American dream and the city and its ideas."

That will include disasters such as the murderous Draft Riots of 1863 and the Triangle Shirtwaist factory fire of 1911, as well as the political corruption of Boss Tweed's Tammany Hall and the misery of the tenement district.

But out of those sad chapters came the nation's first housing and health laws, and the construction of landmarks such as gigantic Brooklyn Bridge, the subway system and Central Park.

And always, New York was, in the view of writer E.L. Doctorow, "a universe of totally disparate intentions."

There were disparate people as well, arriving year after year to replace the original Dutch and English. Today, said Burns, 180 languages are spoken in New York, making it what the film calls "the undisputed economic and cultural capital of the world," often its most "foreign" place to other Americans.

The film, told with a mix of archival photos, drawings and footage, 42 on-screen commentators and 22 off-screen voices, begins in 1609 as the ghostly image of Henry Hudson's 80-ton sailing ship gradually emerges into what would be called New York Harbor. Hudson had been looking for a connection from Europe to China, but what he found was a fine place for a commercial port that one day would become a cauldron of capitalism.

As Nieuw Amsterdam, the city was founded in 1624 by 110 colonists, most of them French-speaking Belgian Huguenots, who set up a trading center for the Dutch West Indies Company.

"New York was founded for no other reason than to make a buck," says narrator David Ogden Stiers.

And these were people who knew how. Indeed, the 60 guilders -- less than $600 -- they paid for all 14,000 acres of Manhattan was truly a steal.

"In grappling with the material, we arrived at a number of themes which we have been able to utilize," said Burns. "One of the central themes was that New York has always been a commercial venture from the start."

As such, a century and a half later, New York had expected to become the capital of the new nation. After all, in 1789, the first government, having no permanent home, had established itself for the time being next door to the Wall Street home of Alexander Hamilton, George Washington's secretary of the treasury.

But Thomas Jefferson, the secretary of state who was living in New York while the government was getting itself organized, concluded the city was "a sewer filled with all the depravity of human nature."

So in 1790, Jefferson offered Hamilton a deal: He would approve forgiveness of New York's Revolutionary War debt, and those of other northern states, if the new capital were established alongside the Potomac River, convenient to Virginia and nearer to Washington's home and his.

As former senator Daniel Patrick Moynihan (D-N.Y.) recounts the tale, bristling at the thought, Hamilton reluctantly agreed to "move the capital of this new nation from its natural site in Manhattan to a swamp on the banks of the Potomac."

"Moynihan, he's an American patriot, but really he's a New York patriot," remarked Burns.

Burns went on to explain what had been at stake: "In the struggle over the capital were all the tensions that were going to give rise to the Civil War: North and South, country and city, an agricultural society and a dawning mercantile -- really, the beginnings of the industrial -- society.

"The Virginia Tidewater planters were worried that the industrial North was going to intensify and build and roll over the rest of the country. You see senators from Indiana worrying about the gathering of power in New York, concerned that what New York stands for is northern industrial might."

Then the co-producer of "The Civil War" and "New York: A Documentary" drew an interesting conclusion: "The Civil War wasn't really caused by Washington," he said. "The Civil War was caused by New York."