These men got their start with start-ups and brought their business chops to politics. See how they fared.

You may know these leaders for their political prowess, yet they all began as entrepreneurs and business leaders. Once they got into the political arena, their self-starting mentality helped them push forward with difficult and historical decisions. Regardless of their party affiliations, tenacity is their unifying trait.

Warren G. Harding

Harding, who served in the White House from 1921-1923, was born into a family of entrepreneurs. Harding’s father owned a newspaper business in Ohio, so the 29th President knew the trade well from a young age.

In business: Harding purchased his father’s paper–the Marion Daily Star–for $300 at the age of 21; he sold his share of the paper in 1923 for $550,000 ($7 million in today’s money).

In politics: Harding was known for his powerful public speaking. His way with words, surely aided by his involvement in the Marion Daily Star, secured his Republican presidential nomination in 1920. Harding’s alliance with the press translated well for his public image as he strove to carry out his campaign promise: “Less government in business and more business in government.”

George H.W. Bush

After graduating from Yale in 1948, Bush set his sights on the blossoming oil industry in Texas, where he prospered as both a businessman and a politician.

In business: Bush got his start in the oil industry as an equipment clerk for a family friend at oil company IDECO in Odessa, Texas. Shortly thereafter, Bush partnered with neighbor John Overby to start the Bush-Overby Development Company. Bush used investments from his family, his father’s Wall Street connections, and other notables (including Washington Post owner Eugene Meyer) to fund the venture. In 1953, the company merged with another independent oil company to create Zapata Petroleum Corporation.

In politics: Known mostly for his foreign policy victories, Bush was unable to win reelection–owing, in part, to what was seen as frivolous spending at home. He may have forgotten that the money he used as President belonged to U.S. taxpayers, rather than investors and family connections.

Ross Perot

The son of a Texan cotton broker, Perot showed his out-of-the-box attitude at a young age. As a salesman for IBM in the mid-1950s, Perot was a fast and furious employee; one year, he even filled his annual sales quota in two weeks.

In business: Perot tried to pitch his ideas to IBM, but to no avail, so he started his own company instead. In 1962, he founded Electronic Data Systems, a data processing service. EDS’s first large contract came from the U.S. government, which commissioned EDS to computerize Medicare records. In 1984, General Motors bought controlling interest in EDS. Perot was also an angel investor in Steve Jobs’s company NeXT, which sold to Apple in 1996 for $429 million and 1.5 million shares of Apple stock–and in 1988, Perot founded Perot Systems Corporation, which was acquired by Dell in 2009 for $3.9 billion.

In politics: Although Perot never held office, he did help create the Reform Party and ran for President twice–once under his party’s banner and the other as an Independent. Perot’s tenacity and ability to sell gained him national attention and made him one of the most successful third-party candidates ever to run for presidential office.

Michael Bloomberg

The three-term New York City mayor has had great success in more than a decade in office. Although he assumed his role in the wake of the 9/11 attacks, he has managed to create jobs, lower crime, and push for a more unified city.

In business: Bloomberg worked on Wall Street at Salomon Brothers until the investment firm was bought in 1981. With his severance package (a reported $10 million), Bloomberg started a media company focused on providing up-to-date business information to investors. Today, Bloomberg LP is a massive media company with more than 13,000 employees and multibillion-dollar revenue.

In politics: Economic growth and job creation have steadily increased in the city under Bloomberg’s watch. His recent devotion to the growth of technology in the city goes hand in hand with his background in digital media.

Darrell Issa

Issa is consistently one of the wealthiest members of Congress. The representative from California’s 49th district also holds an Inc. Entrepreneur of the Year title, which he was awarded in 1994.

In business: In the early 1980s, Issa founded Directed Electronics, which within a decade became the largest manufacturer of auto antitheft devices in the country. Issa himself recorded the Viper system’s signature warning: “Step away from the car.” Issa moved the company from Cleveland to Southern California and served as its CEO until he was elected to the U.S. House of Representatives in 2000.

In politics: Issa may be best known for his contribution to the recall of former Democratic California Governor Gray Davis in 2003. Issa’s success in gathering forces for a common cause can be traced back to his days as a self-starter in Ohio as he gathered investors for his early business ventures.

Mark Warner

Warner’s political interest goes back to college, when he studied political science at George Washington University and worked as an aide for a number of U.S. senators, learning about telecommunications law. Warner applied this knowledge to his business ventures in the early 1980s.

In business: Warner made a substantial fortune as a broker of mobile-phone-franchise licenses before starting venture capital firm Columbia Capital. His firm was one of the early investors in Nextel; Warner also co-founded Capital Cellular.

In politics: By the time Warner left office as governor of Virginia in 2006, Forbes had named it the nation’s “best state for business.” Currently a U.S. senator from Virginia, Warner has enlisted the help of technology companies to identify headstones with errors and headstones that have been misplaced at the Army’s Arlington National Cemetery–at no extra taxpayer cost.

Bob Corker

After humble beginnings in Tennessee, Corker took his first job as a construction superintendent. After four years in the position, he had saved enough capital to start his own business.

In business: Corker used his $8,000 in savings to start a construction company, Bencor, in 1978. The firm began to land large contracts in and around Chattanooga, and by the mid-1980s, Bencor was operating in 18 states. Corker sold the company in 1990.

In politics: In 1994, Corker was appointed Tennessee’s commissioner of finance and administration, charged with tightening the state budget and creating jobs. From 1993 to 1997, unemployment decreased 0.5%. As a U.S. senator, Corker is a member of the Banking, Housing, and Urban Affairs Committee.

Mitt Romney

The Republican presidential candidate worked for nearly 10 years at management consulting firm Bain & Company, helping it out of financial hardships, before leaving with other colleagues to start a private equity group.

In business: Romney co-founded Bain Capital in 1984. Today, the company is listed as one of the largest private equity firms in the world. One of Bain’s first investments was in office-supply company Staples.

In politics: As governor of Massachusetts, Romney created jobs and helped balance the state budget. He showed his money-raising skills as the chairman of the Republican Governors Association during the 2006 election, raising $27 million for candidates running for the House.

This article was syndicated and originally appeared on the Inc.com website