John D. Rockefeller Sr.
John D. Rockefeller Sr. was, by most measures, the richest man in history.
He made his fortune by squeezing out efficiencies that made Standard Oil synonymous with monopoly -- and significantly lowered fuel prices for everyday consumers.
The government broke up Standard Oil in 1911, but Rockefeller's hand can still be seen in spinoff companies such as Exxon Mobil (XOM) and ConocoPhillips (COP), which have benefited from the infrastructure and research-and-development advances inherited from their parent.
Rockefeller retired at the beginning of the 20th century and for the next four decades devoted himself to philanthropy. More than 70 years after his death, he remains one of Wall Street's great figures.
Andrew Carnegie
Andrew Carnegie loved efficiency. His steel mills were always on the leading edge of technology. Carnegie also had an excellent sense of business timing, snapping up steel assets in every market downturn.
Like Rockefeller, Carnegie spent his golden years giving away the fortune he spent most of his life amassing. Though less well-known than some of his contemporaries, Carnegie built a legacy as a strong and moralistic leader.
Thomas Edison
There is no doubt that Thomas Edison was brilliant, but it was his business sense, not his talent as an inventor, that clearly showed his intelligence.
Edison took innovation and made it the process now known as research and development. He sold his services to many other companies before striking out on his own to create most of the electrical-power infrastructure of the United States.
While Edison was a founder of General Electric (GE), many enterprises today owe their existence to him, including the Edison Electric Institute and New York utility company Consolidated Edison (ED).
Although Edison had far more patents than he did corporate ties, it is the companies that will carry his legacy into the future.
Henry Ford
Henry Ford did not invent the automobile. He was among a group of competitors working on motorcars -- and arguably not even the best of the bunch. His rivals were selling cars at prices that made them affordable only by the rich. Ford put the rest of America on wheels, unleashing the power of mass production in the process. His Model T was the first automobile mass-produced on assembly lines and marketed to middle-class consumers, as long as they liked black, the only color available.
Ford's progressive labor policies and his constant drive to make each car better, faster and cheaper made certain that his workers and everyday Americans would think of Ford Motor (F) when they shopped for a car.
Charles Merrill
Charles Merrill brought Wall Street to Main Street. After the 1929 stock market crash, the general public had sworn off anything more financially sophisticated than a savings account. Merrill changed that by using a supermarket approach to equities: He sacrificed brokers' large commissions in order to serve more people, making up his money on volume.
Merrill offered free classes on investing to clients of the company that was to become known as Merrill Lynch, and he published rules of conduct for his company that sought to make sure his employees put customers' interests first.
Sam Walton
Sam Walton picked a market no one else wanted and instituted a distribution system no one had tried in retail. By building warehouses between his Wal-Mart Stores (WMT) outlets, Walton saved on shipping costs and shortened delivery times.
Walton also instituted state-of-the-art inventory controls, enabling his company to sell merchandise for less than his competitors could. Rather than booking all of the savings as profits, Walton passed some on to his customers.
Charles Schwab
Charles Schwab took Charles Merrill's love of the little guy and belief in volume over price into the Internet age. While Merrill had lured the individual investor back to the market after the 1929 crash, Schwab has made it cheap enough for him to stay.
Schwab was the first businessman to offer discount brokerage services to individual investors after May 1, 1975, the date brokerages moved from fixed commissions on securities transactions to negotiated fees.
Schwab's company cut costs by trimming its research staff, stock analysts and financial advisers. From a bare-bones base, he added features that mattered most to his clientele, such as 24-hour service and additional branches.
Walt Disney
Walt Disney was a gifted animator for an advertising company in the late 1920s when he began creating his own animated shorts in a studio garage. One of his characters, Mickey Mouse, was inspired by the mice that roamed his office.
The commercial success of Mickey Mouse allowed Disney to hire other animators, musicians and artists to create a cartoon factory. Disney and his crew turned that early success into a cultural juggernaut including amusement parks, TV shows and movie studios.
Today, the company (DIS) that bears the animator's name is the nation's largest media and entertainment conglomerate.
Bill Gates
When people describe Bill Gates, they often use the words "rich," "competitive" and "smart." Of these traits, it's Gates' competitive nature that allowed him to carve out his fortune.
Gates fought and won business wars over both browsers and computer operating systems, and he used the profits to fund future fights and ventures.
The Xbox video-game console is just one of the many sideline businesses financed by Microsoft's (MSFT) massive war chest. (Microsoft is the publisher of MSN Money.)
Steve Jobs
Unlike the others on this list, Steve Jobs may still be approaching his greatest achievements. Jobs co-founded personal-computer pioneer Apple (AAPL) in the 1970s and was forced out of the company in a power struggle with the board of directors in 1985. Since returning to Apple in 1996, Jobs has transformed the company into a consumer-electronics powerhouse with such projects as the iPod, iPhone and iPad.
Earlier this year, Apple jumped past Microsoft to become the nation's biggest tech titan in terms of market value. Many analysts think it's only a matter of time before Apple leaps past Exxon Mobil to become the nation's biggest company.