Forbes estimates that there are around 500 billionaires in the United States, with about 70% having built their wealth on their own and the other 30% inheriting it. In business, being a tech geek isn't the only path to wealth these days. People have been joining the billionaires list from a number of different industries in the past few years.

So where will you find these super-rich businesspeople? Read on for a look at the five states with the most billionaires, along with the industries that build wealth in each state. We'll use 2013 data, as Forbes doesn't reveal the full roster of U.S. billionaires until its list of the world's richest comes out in spring.

1. California

The tech industry has put California at the top of the list, with 111 billionaires. Silicon Valley has created huge amounts of wealth over the years, as its cluster of technology talent constantly attracts even more talent and creates new businesses that upend incumbents and create value from new innovations and technologies.

In recent years, Facebook (NASDAQ:FB) has been the state's biggest source of billionaires, with Mark Zuckerberg, Dustin Moskovitz, Chris Hughes, Peter Thiel, Sean Parker, and Sheryl Sandberg, among others, making the list. Two more joined the Facebook billionaires' club this year after the company purchased WhatsApp for $19 billion. That purchase made billionaires out of WhatsApp co-founders Jan Koum and Brian Acton.

2. New York

New York, home to the financial capital of the world, has the second-highest number of billionaire residents, with 88. The state's list is largely made up of financiers and fund managers who built their businesses by helping other people invest their money. Besides David Koch, Michael Bloomberg, and Rupert Murdoch, the list reads like a veritable Who's Who of the investing world: Carl Icahn, George Soros, Stan Druckenmiller, Daniel Loeb, David Einhorn, Nelson Peltz, Bill Ackman, and many others.

3. Texas

Texas, with 51 billionaires, places third. The state's lack of an income tax has probably helped attract billionaires from several industries, but most of the Lone Star State's list is made up of people from the energy industry -- particularly oil and gas pipelines. The richest person in the state is Richard Kinder, whose Kinder Morgan (NYSE:KMI) is the largest pipeline company in the U.S. and plans to get bigger and continue growing its dividend. Other notable energy billionaires include the Duncan Family of Enterprise Products Partners LP (NYSE:EPD), Jefferey Hildebrand of Hilcorp, and shale investor Trevor Rees-Jones.

There is a motley bunch of other billionaires from Texas, including Dell's Michael Dell, Beal Bank's Andrew Beal, Ross Perot, Jr., Dallas Mavericks owner Mark Cuban, and Dallas Cowboys owner Jerry Jones.

4. Florida

Like Texas, Florida lacks an income tax, and that certainly attracts people to the Sunshine State, as do its weather and cost of living. The state claims 37 billionaires, some of whom are homegrown, but many of whom have decided to make Florida their home after making their money elsewhere. Notable Florida billionaires include Wilbur Ross, Sears Holdings' (NASDAQ:SHLD) Eddie Lampert, Franklin Resources' (NYSE:BEN) Charles Johnson, Carnival's (NYSE:CCL) Micky Arison, Best Buy's (NYSE:BBY) Richard Schulze, Rockstar energy-drink founder Russ Weiner, Subway founder Fred DeLuca, and Wayne Huizenga, founder of Waste Management (NYSE:WM), Blockbuster Video, and AutoNation (NYSE:AN).

5. Illinois

Rounding out the top five is Illinois, with 19 billionaires. Finance and real estate moguls top the state's list of billionaires, with Ken Griffin of alternative-investment giant Citadel at No. 1. Guggenheim Partners' Mark Walter and Morningstar's Joe Mansueto are the state's other finance billionaires. In real estate, Sam Zell leads the way in Illinois, with the members of the Pritzker family, founders of Hyatt Hotels (NYSE:H), also making the list.

Slow and steady path to riches

Most of the United States' billionaires became wealthy slowly by building valuable companies in areas that many people find to be boring. One of the great things about America is that you're free to start your own business and compound your investments over time to the point where you, too, can become a billionaire.