The American Dream is alive and well in Menlo Park.

Facebook is going public Friday, after raising $16 billion Thursday at a valuation of more than $104 billion. Shares opened for trading shortly after 11 a.m., at $42.05, up slightly from the previously announced price of $38.

This is the largest VC-backed tech IPO ever—10 times bigger than Google's IPO in 2004, and the third largest public offering in the history of the United States, just behind General Motors and Visa. Having grown in eight years from a scrappy start-up, the company, which has created more than 3,000 jobs, and made $3.7 billion revenue last year, today enters a new phase in its trajectory.

Underwriters for the deal, who stand to make millions in fees and even more in shares owned, included Morgan Stanley, JPMorgan Chase, and Goldman Sachs. Yesterday, Bloomberg reported that Goldman Sachs will sell about $1 billion of stock in Facebook after the IPO, "cashing out almost half their stake after the social network doubled in value."

With its IPO, Facebook seals its status as a legendary tech company in Silicon Valley, rivaling industry stalwarts like Intel and Apple. Born out of a Harvard dorm room, the world's largest social network—with 900 million usesrs worldwide—may have once been seen as "a novelty," has grown in eight years from an online place a few college students tallied their social connections to a global communication platform.

More than any other enterprise on the Web, Facebook has become a a prime aggregator of user data, and accordingly, a prime vehicle to deliver advertisements to potential consumers. On the Web, data is money. In 2012, digital advertisers will spend more than $32 billion to get potential customers to click their ads; Facebook will take a substantial chunk of that spend.

Facebook filed to go public on February 1. In the company's S-1, Zuckerberg opined that "Facebook was not originally created to be a company," but that "It was built to accomplish a social mission—to make the world more open and connected."

That sentiment certainly sounded like an investor-wooing kin to Google's "Don't Be Evil," but perhaps Facebook's quantifiable data does pale in significance compared to the myriad of unquantifiable connections, relationships, and conversations the networked has spawned since it was founded in 2004. For better or worse, with nearly a billion users, Facebook has fundamentally altered the way people interact, socialize, plan events, share information, hunt for jobs, flirt, date, and memorialize death. It's not hard to make the argument that Facebook has fundamentally altered the way humans think about the world and each other. Could the Arab Spring have happened without Facebook? Probably not.

Facebook has also forced governments to reflect on the nature of personal privacy in the online age. Scores of legal and academic criticism has mounted over the years in the wake of data leaks that resulted in the dissemination of mounds of personal information to third party advertisers, not to mention the hundreds—if not thousands—of HR debacles that resulted from the posting of lewd status updates and scandalous photos.  (As of 2011, four percent of the world's photos—as in, all images captured throughout human history—were being hosted on Facebook. It also stores more than 10,000 times the amount of photos in the Library of Congress.)

In the wake of negative PR surrounding Facebook's mysterious methods of obtaining, retaining, and selling data, The Wall Street Journal formed a task force in 2009 titled "What They Know." The investigation revealed the depth of Facebook's knowledge of its users, from simple facts like a user's birthday to the sexual preferences of that user's closest friends. One book, The Facebook Effect, claims that Zuckerberg even experimented with algorithms that would be able to predict users' breakups.

Still, regardless of personal perceptions or attitudes about Facebook (whether or not you believe it is or evil, or if the site is just a fad) the company has been a relentless force in captivating the ethos of the country. In under eight years, the company has shot from a few 19-year-old hackers in a dorm room to an established firm that has managed to dominate the cultural zeitgeist.  Countless books have been written about the company, and The Social Network, a film about Facebook’s origins penned by Aaron Sorkin, received eight Academy Award nominations and won three.

In 2010, Time named Mark Zuckerberg "Person of the Year," adding the young founder to the auspicious list of magnates that has included Mahatma Gandhi (1930), Martin Luther King, Jr. (1963), and Barack Obama (2008).

Facebook has become so much a part of daily conversation that it's even shifted the etymology of English words in its vocabulary. The word itself, Facebook, can be used as a verb. So can "friend." To Like something is now altogether different than liking something. Poking is still a bit creepy, both on Facebook and in real life.

In less than a decade, the company's IPO has made a slew of people inconceivably wealthy, especially Zuckerberg himself, who is now worth about $18 billion (making him the richest self-made 28-year-old on the planet). 

Plenty of others are cashing in too, from Facebook’s initial investor Peter Thiel (who will earn about $2 billion) to Facebook’s graffiti artist, David Chu, who was paid in company stock that is now worth upwards of $200 million. Bono, the front-man for U2 who invested about $120 million in Facebook in 2010, will see his investment quintuple to more than $1 billion. 

Rumors of a Facebook IPO started swirling in the Valley in 2009, shortly after Digital Sky Technologies bought two percent of Facebook for $100 million. When the company officially filed its SEC papers in February, critics began to question Zuckerberg’s ability to lead what would become one of the world's largest publicly-traded companies. 

The Mark Zuckerberg Show

This week Zuckerberg raised eyebrows when he showed up to the company's IPO roadshow in a black hoodie. Some doubted his ability to cast a professional image to the scores of bankers and Wall Street executives sizing him up. 

"He's actually showing investors he doesn't care that much," one analyst told Bloomberg TV.  

But hoodie or suit, with 57 percent of the voting shares, Zuckerberg will retain a level of control rarely seen in public companies (most recently, Google's trio of founders held on to 40 percent when it went public). This means Zuckerberg will have an absolute say over election of directors, any sales of assets, and all mergers and acquisitions.

The world got a taste of this one-man-show mentality in April, when Facebook bought Instagram for $1 billion—a deal worked out privately between Zuckerberg and Instagram CEO Kevin Systrom without the input of the company board or investors.

From the company's start, Zuckerberg made strategic decisions about equity, employees, and the structure of the company. And when former Napster founder Sean Parker became president of Facebook in 2004, he helped Zuckerberg gain two seats on the company's board. 

In November 2009, Facebook's board of directors voted to establish a dual-class stock structure, moving the existing shareholders stock from Class A to Class B shares, which carry 10 times the voting power. Dual stock-structure doesn't necessarily give Zuckerberg final say in every decision, but his votes carry so much weight that it makes him an incredibly powerful player in the company—even apart from his status as founder and CEO.

Navigating Obstacles Ahead

For current Facebook employees, especially those who joined the company early on, the IPO means newfound liquidity. This has several implications for the company. Beyond trips around the world and expensive European cars, Facebook managament faces a potential attrition from current employees who want to strike out on their to launch their own ventures. And by trading in stock for cash, several employees will have the runway to make that decision.

"I think it's always a risk when you have a liquidity event," said one former Facebook employee, speaking on the condition of anonimity. "Facebook mainly hired entrepreneurs in the early days, and so a lot of those entrepreneurs are going to be starting their own companies in the next 12 months."

The road ahead for Zuckerberg and Facebook will be filled with hurdles

No longer a start-up, the company will need to ease into life as a large, publicly traded company that answers to shareholders and board members—not just Zuckerberg. The challenge, it seems, will be to retain the same hacker culture the company was founded with—and thrived on—while maintaining the scale and growth investors will expect.

"At Facebook, the issue is to continue to grow and provide vision for company and have deep sense of meritocracy," says Brad Silverberg, a former Microsoft executive and founder partner of Ignition, a Washington-based venture capital firm. "Where things break down is in companies where they get bigger they have a 'have-and-have-not mentality.' The role of politics interferes and then you get some larger issues—and you get the best people leaving."

The Making of Start-up History

Facebook launched in 2004, as The Facebook. As the famous start-up tale goes: Zuckerberg and a few friends ran the invite- and student-only social network from his Harvard dorm room. It quickly expanded to other Ivy League schools. By the end of 2005, Zuckerberg had taken in former Napster founder Sean Parker as the company's first president, and also raised $13 million in funding from Accel Partners.

Along the way, Zuckerberg fought highly-public legal battles. In late 2004, Harvard students Cameron and Tyler Winklevoss, who had hired Zuckerberg to build their social network, ConnectU, filed a lawsuit claiming TheFacebook was their idea. Around the same time, Zuckerberg’s co-founder Eduardo Saverin also sued over equity dilution. (By 2009, both cases settled: No details on the Winklevoss case, but Saverin walked away with five percent equity in Face book.)

After opening up the service beyond college students in 2005, the company experienced a period of rapid growth. By 2007, the sevice took in new members at a 250,000-per-day rate. In 2009, at 200 million users, Facebook usurped MySpace as the world's largest social network.

In a 2009 interview, the typically tight-lipped Zuckerberg gave some telling insight into his company's future:

I think that one of the most important trends over the next 10 or 20 years is how the world opens up. Will it be done in such a way that people have complete control of their information, or will it be done in a way where they don't and that information is just out there? Facebook is really invested in making sure that it's the former one, where people can always control what their identity is and what information of theirs is being shared with different people, and I just think that matters a lot. I think that's one of the key questions for our generation.

 Since the company filed to go public in February, Zuckerberg has been legally required to remain quiet to press and investors. But now, things have changed. Zuckerberg will be accountable to shareholders, to his board, and to employees in a public arena he has yet to face. In the coming months, the public will get a chance to witness how Zuckerberg handles being the 28-year-old CEO of the world's most important technology start-up.