As the debate over travel bans continues, it's worth remembering the importance of immigrants on America's business landscape.

Some of the most iconic companies in the Fortune 500 were started by the children of immigrants. Apple co-founder Steve Jobs, famously, is a child of a Syrian immigrant. Other founders with immigrant parents include Walt Disney (Canada), The Home Depot's Bernie Marcus (Russia), Amazon's Jeff Bezos (Cuba) and Henry Ford (Ireland).

And the number of notable businesses started by immigrants themselves is just as impressive. In 2010, Fortune 500 firms founded by an immigrant directly generated more than $1.7 trillion in revenues, according to Partnership for a New American Economy, a business group whose board includes Disney CEO Bob Iger, Rupert Murdoch and Michael Bloomberg.

Here's a look at some of the most well-known U.S. companies started by immigrants. Some of them may surprise you.

The cable giant (and parent company of CNBC) was launched by Daniel Aaron, who was born in Giessen, Germany, in 1926. He and his family immigrated to the United States in 1937 to escape the Nazi government. In 1963, when Philadelphia entrepreneur Ralph J. Roberts bought a small cable television system, he insisted that Aaron run it. Together the two built Comcast into the largest cable television provider in the United States.

While it's soon to be a subsidiary of Verizon, there's no arguing Yahoo's impact on the formative days of the internet. One of the company's co-founders, Jerry Yang, was born in Taiwan and moved to America with his mother in 1978. At the time, he knew only one word in English — "shoe" — but became fluent within three years. Yahoo, where he also served as CEO from 2007–2009, was valued at $125 billion in 2000, but Verizon will pick it up for just $4.48 billion.

Neither of the namesakes of this consumer products giant were born in the United States, actually. William Procter was born in England, where he served as a candle maker, among other jobs. He moved to Cincinnati in 1832 at the age of 31. His father-in-law introduced him to James Gamble, an Irish-born soap maker who had married Procter's wife's sister. The pair launched their company in 1837. Last quarter it reported revenues of $15.6 billion.

One of the big success stories to come out of the dot-com boom, eBay could easily have been a French company. Founder Pierre Omidyar was born to Iranian immigrant parents in France in 1967. He made his way to the United States as a child, creating the online auction site (originally called Auction Web) in 1995. Earlier this year, Omidyar launched a new venture, donating $100 million to support investigative journalism and fight "fake news."

Cousins and eventual brothers-in-law, Charles Pfizer and Charles Erhart, were both born in Ludwigsburg, Germany. The two made a pact to immigrate to the United States in the mid-1800s, where they launched the now iconic pharmaceutical company in 1849, with a deworming agent as its first product. Today Pfizer is one of the largest pharmaceutical companies in the world, thanks to drugs like Lipitor and Viagra.

Born in Paris, E. I. du Pont sailed to America in 1800. Within two years he had established his business, a gunpowder manufacturer that went by the name E. I. du Pont de Nemours and Co. The name has since been shortened and the focus shifted to manufacturing materials, like Kevlar and GMO seeds (among many other items). The company announced a merger with Dow Chemicals in 2015 in a deal valued at $130 billion. That deal is expected to close in August.

Some might think of Alexander Graham Bell as a famous American, but the inventor of the phone and founder of Bell Telephone (which was acquired in 1885 by American Telephone and Telegraph, another Bell start-up) was actually born in Edinburgh, Scotland. Bell became a naturalized citizen of the United States in 1882, when he was 35. The company held a monopoly on telephone service domestically until 1982. Today it has more than 264,000 employees worldwide.

Co-founder Sergey Brin left his birthplace of Moscow in 1979 at the age of six to come to America with his parents, who were hoping to escape Jewish persecution. After earning his degree in mathematics and computer science at the University of Maryland at College Park, he famously met Larry Page at Stanford University, where the pair stopped pursuing their PhDs and started Google in a garage.

This private spaceflight company is just one of many founded by Elon Musk, who was born in South Africa. He first moved to Canada in 1989, then made it to America in 1997 when he transferred to the University of Pennsylvania. He became a U.S. citizen in 2002. Beyond SpaceX, he also co-founded the company that (through mergers) would become PayPal, automaker Tesla and solar energy company SolarCity. Musk's current net worth is estimated to be $16 billion.

The company that's now one of the top steel manufacturers in the world owes a lot to a 1901 merger with Carnegie Steel, founded by Andrew Carnegie. And while Carnegie is one of the names most associated with American wealth (along with the Rockefellers and Morgans), he was actually born in Dunfermline, Scotland. He immigrated to the United States in 1848 with his parents at the age of 13. When he sold Carnegie Steel for $480 million, it made him the richest person in the country — money he ultimately used for philanthropic purposes.