(FORTUNE Magazine) – You'll hear different accounts of the cause. But virtually all agree that Charlie Cawley was livid. It was the first weekend in May five years ago, and chateau country--as the rolling hills dotted with du Pont mansions are known--was in full bloom. Le tout Wilmington, Del., had gathered for a genteel annual celebration known as Point-to-Point. A benefit for Winterthur, a du Pont estate turned museum where the event is held, Point-to-Point features a series of equestrian events, including races and a procession of ornate carriages guided by footmen in period finery. Not only does the horsey set attend, but so does just about everybody else in the area, including corporate executives, who socialize in the tents their companies sponsor.

The tents, it turns out, may have been the problem. Some say that Cawley--who, no Delawarean needs to be told, is the co-founder and driving force behind the smashingly successful credit card company MBNA--was in a snit over the location of his company's tent. Others say he was peeved that the barons of Point-to-Point had rejected his nominee for the charity's board.

Whatever the cause--and MBNA disputes the notion that he was displeased about anything--Cawley isn't one simply to throw a mogul's tantrum and pronounce himself satisfied. So he pulled MBNA's sponsorship from Point-to-Point--and then proceeded to organize a new event, a walkathon that MBNA's charitable foundation has held each year since. On the same day as Point-to-Point, as it happens. Now the 13,000 MBNA employees and family members who participate in the walkathon arrive late to the old du Pont mansion, if they arrive at all. The MBNA event even makes use of the main road from Wilmington to Winterthur, choking traffic heading out to the estate.

Not since Beverly Hills was stormed by hillbillies has the world seen such a clash between the old gentry and the new. Yes, it would be easy to dismiss it as a tempest in a gilded teapot, a mere triviality in a world riven by bloody conflict on three continents. That view would be correct, of course. But then, who can resist the spectacle of a collision between what may be America's original corporate culture--Du Pont--and an upstart, mildly messianic cadre of executives with money and ambition to spare? From the invasion of blue-blood redoubts to the changing face of Wilmington's downtown; from MBNA's growing political brawn to its, well, distinctive sartorial philosophy, the credit card company is shaking the old order in the first state of corporate America.

Ah, the duchy of Delaware, a realm deeded to the Du Pont company centuries ago--if not actually by the Founding Fathers, then by the verdict of history. Delaware has always been the Liechtenstein of America, a postage stamp of a state (100 miles long) with a minuscule population (780,000) but a critical role to play in the running of the American economy: More than 300,000 companies and 200,000 other business entities take advantage of the state's favorable laws and taxes and choose to be incorporated there.

But Delaware ain't what it used to be. Du Pont has undergone a painful decadelong redefinition, cutting its ranks in the state from 25,000 to 9,900. At the same time, MBNA has blossomed from 3,000 employees in Delaware to 10,500, surpassing Du Pont in the last year as the state's largest private employer. MBNA and its leader are increasingly playing the role--patron of business and philanthropy--once reserved for Du Pont and the du Ponts. (The company and the family render the name differently.) "Charlie Cawley is a strong personality," says former governor and presidential candidate Pete du Pont. "If he decides, much as my grandfather might've decided in 1950-something, that something's going to happen, it's going to happen."

That doesn't mean people have to like it. "There is a clash of cultures," says William Lee, a retired state judge and former gubernatorial candidate. The rub is between the low-key, highbrow, extravagant- but-somehow-discreet way of life shared by the du Pont family and the hard-driving, up-by-the-bootstraps style of MBNA. And even if the credit card crowd is doing essentially what the chemical clan did 200 years ago, that doesn't mean it's in for a gracious reception. "Charlie Cawley is not the first person to come to Delaware and believe that, because he makes a lot of money and gives a lot of money, it should admit him to the highest social circles," says Lee. "And it doesn't work. You can't buy your way in."

Apparently, you can. Just outside Wilmington lies Greenville, Del., a leafy sanctuary of old blue-granite mansions and even older money. Here, in this last stronghold of du Pont patrimony and 100-acre estates, the word "subdivision" could refer to a 12-acre property. And here, MBNA executives have been squeezing their way in, little by little.

How can you tell? The cars are one giveaway. "Du Ponters have always kept a low profile," says Pat Stull, a realtor with Patterson Schwartz in Greenville. "They don't buy fancy cars, even though they could afford to. And MBNAers do." Consider this example: Eighty-two-year-old family patriarch Irenee du Pont, who lives on an estate called Granogue (which might not be considered as keeping a low profile in some parts) and is estimated to be worth half a billion dollars, drove a 1980 Chevette for nearly 20 years. Lest you suspect him of excessive parsimony, it should be noted that he did buy the Chevette new. (He has since upgraded to a '99 Oldsmobile Intrigue.)

MBNA's Cawley, by contrast, maintains a collection of antique cars whose quantity--about 100--might be significantly greater but for an edict issued by his wife. Cawley cuts a dramatic figure in his vintage cars, but an even more striking one in his alternative mode of transportation: a helicopter. He regularly choppers out from two helipads, one at MBNA's Greenville office (just blocks from his home) and a second, a 15-minute drive away, in downtown Wilmington.

"When MBNA folks make a million dollars," says Stull, "they're not afraid to spend it!" Like many high-end home-buyers these days, she says, MBNA executives are given to spending a lot to buy a gracious old house--and then promptly shelling out even more to rip out the kitchen and bathrooms.

The rehab extends all the way to Wilmington proper, where, it's not an exaggeration to say, MBNA has saved the downtown.

For a century, Du Pont's sober gray headquarters has presided over historic Rodney Square in the heart of Wilmington. But since MBNA arrived in the city in 1995--at one corner of the square--the two companies have been headed in opposite directions. MBNA's graceful neoclassical headquarters has been augmented by four clones, all of them in the cream and green of the company's logo. It has also renovated aging row houses for its employees. In the meantime, Du Pont has unloaded three of its four buildings in downtown Wilmington.

You can't avoid the symbolism. Du Pont, which owned four golfing clubs for decades, sold one company facility, and with it one of its clubs, to MBNA a few years ago. And Du Pont had to endure the indignity of seeing the ground floor of one of its former buildings turned into a steak house and disco whose investors were Cawley and other senior MBNA executives. Until the establishment closed last year after a brief existence, a crowd dominated by young MBNA employees would dance late into the night just down the hall from Du Pont's former corporate library.

By most accounts, MBNA's staffers tend to be friendly, well dressed, and clean-cut. To many Wilmingtonians, that can mean only one thing: It's a cult. Locals will occasionally mutter the term darkly, as one did on a recent night when a phalanx of MBNA employees occupied the back of the bar at a sleek restaurant called Deep Blue. When the group barked out a few lusty choruses of "Who Let the Dogs Out?" the bartender rolled her eyes.

Some residents are less restrained. One MBNA veteran recalls the reaction she got a few years ago when she was sightseeing in Wilmington with her children. "I had my MBNA badge on my purse," she recalls. "And this couple said, 'Oh, my God--you work there? I heard that's a cult.' Here my kids were sitting with me, and I felt like I was being attacked. Now I take the badge off when I leave the building."

The cult thing even made it into a lighthearted lampoon at the local Gridiron Dinner, an annual bipartisan charitable event in which everybody who is anybody is skewered. MBNA employees and their families were likened to the automatons in the movie The Stepford Wives.

"We certainly don't believe that it is a cult," says MBNA America Chairman Bruce Hammonds. "We'll admit it's not the place for everyone. We're intensely focused on the customer and on attention to detail. And our people do share a similar attitude." (The company declined repeated requests to make Cawley, who is CEO of MBNA America and president of parent MBNA Corporation, available for this article.)

Still, there's no denying that something sets MBNAers apart. In an era of casual, even slovenly dress--many Wilmington companies, including Du Pont, have forgone suits and ties--MBNA has held the line. Tightly.

The men in particular could be mistaken for Secret Service agents. Each appears to have been issued a similar gray or blue suit with a matching conservative haircut. Like prototypical G-men, the MBNA population tends to be youngish (late 20s to early 40s--a decade or two younger than the typical Du Pont employee) and trim in physique. Nearly every employee wears a gold MBNA pin (left lapel, if you please).

It's not just their sartorial regimentation. They share a powerful esprit de corps, bred by a combination of a clearly articulated creed, a devotion to group activities--particularly charitable ones--and a loyalty inspired by the vast array of benefits (everything from in-house dry cleaning to scholarships to antique cars that the company lends employees for weddings) that MBNA staffers enjoy.

The word most often used to describe MBNA's culture is intense. Insular would also fit. And you could probably throw in feisty too. Cawley has been known to put it this way: "We don't have a culture; we have an attitude." Conveniently, that attitude tends to come in sound bites. Maxims are ubiquitous at company facilities: The words THINK OF YOURSELF AS A CUSTOMER are printed over every doorway of every entrance and every office of each MBNA building.

If people seem slow to accept the MBNA crowd, it's worth pointing out that until recently Delaware was populated overwhelmingly by native Delawareans. Even today, it takes only slightly less time for outsiders to be accepted than it would in, say, Japan. In an interview, Wilmington's director of economic development, Richard Pryor, described himself as "new to the community"--and then explained that he's been living in Delaware for 40 years. Similarly, retired state senator Andy Knox was quick to apologize for not being born in the state, though he was willing to concede that he knows it pretty well. He has resided there for 52 years.

The one thing that's truly native to the state, Delawareans agree, is Du Pont, which has been based here for all of its 200 years. It's impossible to overstate the connections and influence of the company and the family (which were more or less one and the same until the 1970s, when du Ponts finally ceded the reins). Family members served as Senators, Congressmen, and governors. Du Ponts owned the only daily newspaper and controlled the largest banks in the state. For decades 10% or more of the legislature was made up of Du Pont employees.

"They were Delaware," says former state chamber of commerce head John Burris. Into the 1980s, if a Delawarean told you he worked for the company, as people routinely did, you didn't have any doubt about which organization he was referring to.

MBNA, by contrast, arrived just the other day--in 1982. Fittingly, it couldn't have happened if a du Pont hadn't sanctioned it. In this case, then-Governor Pete du Pont signed a law that repealed the limit on the interest rates that financial institutions could charge. Banks, including an offshoot of a struggling third-tier bank, Maryland National, poured into the state. And so MBNA was founded in a converted A&P in Ogletown, Del. Cawley, a onetime bill collector who grew up in New Jersey, was given responsibility for the low-priority project. With a focus on affinity cards--those co-branded by everything from football teams to bar associations--and high-end customers, MBNA took off. It's now the largest independent credit card issuer in the world, with $10.1 billion in revenues and $1.7 billion in profits last year.

Whatever wariness there may be toward MBNA, it tends to run quietly under the surface. Delawareans hesitate to criticize a company that has saved the state from what could have been the economic calamity of Du Pont's contraction, and one that has contributed so much philanthropically.

But MBNA became an issue in the 2000 gubernatorial election. Burris, who had pulled out of the race for the Republican nomination months before, emerged from a meeting with Cawley and a dozen other corporate executives in Cawley's office, and announced that he had changed his mind. Although the attendees included two retired Du Pont CEOs and executives from other organizations, the MBNA connection stuck. "The feeling was that the corporate community of Delaware--particularly MBNA--had handpicked him," says Mike Castle, Delaware's Congressman and former governor.

That perception intensified after the Wilmington News Journal reported that Hammonds, the MBNA America chairman, had distributed a memo encouraging MBNA executives and spouses to donate to Burris. Sure enough, within two weeks more than 100 had anted up. By the time of the primary, one-third of Burris' funding had come from MBNA sources. ("MBNA people work together on many things," says Hammonds, "and when we ask people to support candidates who support good government, you find that people in the company are very supportive of that as well.")

Despite being the officially endorsed candidate of the Republican convention, Burris could eke out only a 46-vote victory in the primary and then was pulverized in the general election. It did not go unnoticed that, particularly in the primary, Burris had done poorly in Greenville, home to many du Ponts.

Laird Stabler, a Republican National Committeeman and a du Pont by marriage, insists that many in the family simply liked the other candidate better. And some du Ponts, certainly, maintain close relations with Cawley & Co. But not all the old-timers are throwing out the welcome mat. "I think they resent this kind of newcomer coming in," concedes Stabler. "And there are some who think, Here's a guy whose company is basically run on other people's debt.... So there's some--not resentment, but the fact is that maybe the way that Cawley and MBNA have made their money would not be something that they would want to be involved in."

In the end, perhaps, MBNA can take solace in the fact that there was a time when another company's leaders were making waves in Delaware. That company, of course, was Du Pont.

It took the du Ponts a full century to be accepted. They were a French-speaking, insular clan--evincing a marked preference for marrying their first cousins--in the dangerous business of making gunpowder. And into the first third of the 20th century, the du Ponts were far more colorful than even Charlie Cawley.

Decades-long feuds roiled the family. The hot-tempered Alfred I. du Pont surrounded his estate with a massive wall topped by broken glass. "That wall," he informed the world, "is to keep out intruders, mainly of the name of du Pont." In a fit of pique at his ex-wife, Alfred I. once went so far as to get a pliable state legislator to introduce a bill to change his son's name from Alfred Victor to Dorsey Cazenove. Though the bill was defeated (by two votes), the fact that it was even considered suggests the extent to which the government was willing to entertain the whims of its leading family.

Such a thing could never happen today, of course: Charlie Cawley is said to be happily married.

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