(FORTUNE Magazine) – America is a strange and wonderful country. Some of the wonderful things include minor-league baseball, Wild Turkey, and Aretha Franklin. Then there are the strange things, like lawn ornaments and Tater Tots. Another strange piece of Americana I'm fascinated by is how private entities often perform quasi-government functions. These companies and organizations answer to no one, yet wield tremendous influence over the lives of millions of Americans. The NCAA is one such organization. The Educational Testing Service, or ETS, is another.

Even mightier than the NCAA and ETS, however, are three companies you may never have heard of, though they know an awful lot about you. I'm talking about the so-called credit bureaus, the outfits that rate your credit and determine whether you receive mortgages, loans, credit cards, and insurance coverage--as well as how much you pay for those products and services.

Much has been made of how inconsistent and arbitrary the credit reports are, how they're riddled with errors, and how it's like yanking molars to get those mistakes fixed. I am not here to rehash those gripes, though I'm sure many of them are true. Instead, I would like to answer two simple questions about credit bureaus: (1) Who are these guys? and (2) Who put them in charge anyway?

The names of the three major credit bureaus are exactly what you'd expect: boring and seemingly computer-generated. Let's start with Equifax (EFX, $20), the biggest of the bunch, with operations in 18 countries. Equifax was founded as the Retail Credit Co. in Atlanta in 1899 by brothers Cator and Guy Woolford, who compiled credit records of the city's citizens in a "Merchants Guide" that they sold to local grocers for $25 a year.

Equifax grew through fits and starts and went public in 1965. Since then it's had something of a checkered history. Like other credit bureaus, it became regulated to a degree by the FTC in 1971. Shortly thereafter the company was charged by the government with evaluating its own employees according to how much negative information they could collect about consumers. Equifax says that the charges were related to its insurance and consumer investigation business, and that the information gathered was never used in evaluations of credit ratings. After Equifax volunteered to more carefully monitor the procedures at the insurance and consumer investigation biz, the government dropped the allegations. (The unit was later spun off.) By 1973 the company got big enough that it was sued by the FTC for monopolistic practices. Those charges were eventually dropped in 1982 (by then national computer databases had been developed that made information that was previously compiled regionally available to companies nationally). Later in the 1980s the company launched an ill-fated foray into the lottery business in California. Over the past ten years the company has settled various cases and complaints by states and the FTC over inaccurate reports and conflicts arising from response rates to consumer inquiries.

Despite those blemishes, the credit bureau business has been very good to Equifax. Last year the company had $178 million in net income from continuing operations, on $1.1 billion in revenues. The stock has outpaced the market, climbing from around $4 to $20 in the past decade alone. So next time you get shot down applying for a credit card, think about all those happy shareholders.

Gleaning information about another large credit bureau, TransUnion, is tougher because it is a part of the huge, secretive, privately owned Marmon Group. Marmon may be familiar to you because it is controlled by the Pritzkers of Chicago, one of America's wealthiest families, who also own the Hyatt hotel chain. The Pritzkers founded Marmon 50 years ago as a vehicle for their ever-expanding empire of arcane businesses. Marmon owns or has owned a glove manufacturer as well as makers of railroad cars, auto parts, mining equipment, building materials, Kangol hats, and even "animal-husbandry equipment" (Jamesway Incubators). It took its name from Marmon Motor Car, which built the roadster that won first Indy 500 in 1911.

The Pritzkers also bought and sold Braniff Airlines and purchased Ticketmaster (later selling the bulk of that business to Paul Allen). Oh, I almost forgot. In the midst of all this wheeling and dealing--in 1981, to be exact--Marmon bought a large, failing amalgamation of businesses called TransUnion, which was into railcar and equipment leasing, water treatment, and international trade. It also had a credit bureau, a business that grew from a company called the Credit Bureau of Cook County. Team Street Life called TransUnion, but a spokesperson wasn't too keen on sharing info on its financials. TransUnion does have a website on which it says, "Our database contains more than 200 million files.... This represents the credit activity of every active consumer in the United States." Hmm. Next time you're trying to get a mortgage, just remember: animal husbandry and your credit report.

The third credit bureau, Experian, isn't even domiciled in the U.S. anymore. It used to be TRW's information systems and services unit, but in February 1996 the U.S. conglomerate sold the business to Boston buyout king Tom Lee for about $1 billion. There was a plan to take Experian public around the time of the sale to Lee. A registration statement shows that at the time the company was doing about $540 million in sales with profits of $52 million. Anyway, get this: In November of the same year that Lee bought the company for $1.1 billion, he turned around and sold it for $1.7 billion to a British company called GUS. (Nice one, Tom!)

GUS, as it turns out, is a quirky, 100-year-old company formerly known as The Great Universal Stores Limited. (It used to be just The Universal Stores; the company added the "Great" in 1930--during the Great Depression.) GUS is mostly in the retail catalog business in Britain, though it also runs stores, most famously Burberry (last July it spun off 23% of that in a public offering). GUS also does direct mail and collects and sells other types of data besides credit info. When applying for new insurance coverage, you may find it comforting to know that for many years GUS was run by Lord (Leonard) Wolfson of Marylebone, and later by his cousin Lord (David) Wolfson of Sunningdale, who was also Margaret Thatcher's chief of staff for six years. Rule, Britannia!

So, there you have it. The complete answer to my first question, which was "Who are these guys?" (Aren't you sorry we asked!) And now for the second query: Who put them in charge anyway? Was it a presidential decree? No. Was it an act of Congress? No. Was it an act of God? Nope. It was plain old evolution of the private sector of the economy. Equifax, TransUnion, and Experian just ended up in charge (and living large). Like I said at the top, these companies--and the niches they've created--should be included in any list of American strangeness. Nothing wrong with that, I suppose. But I think it helps explain those discrepancies in your credit reports.

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