What do Google’s Sergey Brin, eBay’s Pierre Omidyar, and Tesla Motors’s Elon Musk all have in common? Each of these serial entrepreneurs who founded companies that have market caps in the tens or hundreds of billions–employing tens of thousands of workers–were born outside the U.S. From Yahoo to Facebook and LinkedIn, each of these innovative companies that have played such a large role in the U.S. economy had at least one founder that was born abroad and then emigrated to the United States.

Immigrants today are more than twice as likely to found businesses as their native-born counterparts and are responsible for more than 25% of all new business creation and related job growth. And while some of these immigrant-led businesses are next-generation startups and small businesses, many actually top the charts when it comes to America’s largest companies. Currently, more than 40 percent of Fortune 500 companies were founded by immigrants or the children of immigrants, according to a study by The Partnership for a New American Economy, a group of governors and business leaders launched by New York City Mayor Michael Bloomberg and Australian media heavyweight Rupert Murdoch. Yet today, more than 200 years after the U.S. declared independence and threw open its doors to immigrants looking for freedom and a chance to realize their potential, the land of opportunity has been inching its doors shut.

A recent study put out by the National Venture Capital Association (NVCA) found that venture-backed companies with at least one foreign-born founder are responsible for an increasing amount of IPOs and subsequent job creation. The study concluded that 33% of venture-backed companies that went public between 2006 and 2012 had at least one immigrant founder at the helm. The study also found that those public, venture-backed companies with at least one immigrant founder represent a market capitalization of $900 billion.

These revenue-generating machines are an enormous boost to the U.S. economy–contributing to the GDP, paying taxes to help lower the U.S. debt, creating domestic jobs (immigrant-founded, venture-backed public companies employ approximately 600,000 people globally with the majority of jobs created in the U.S.) and helping to lift up the standard of living overall.

When I asked Mark Heesen, president of NVCA, why immigration reform is so important not only altruistically for immigrants looking for opportunity but actually selfishly for the U.S. economy, he said: “As Congress debates comprehensive immigration reform, understanding the contributions of high-skilled, foreign-born entrepreneurs to our country is imperative to ensuring meaningful changes to our system. These individuals have founded many of America’s most successful companies, keeping jobs, market value, and innovation here in the United States. Our policies must not only accept, but welcome the next generation of immigrant entrepreneurs who are making even greater strides in starting and growing amazing companies.”

But let America’s immigrant entrepreneurs speak for themselves. From the Greek-born founder of The Huffington Post to the Romanian-born CTO of SAP turned founder of Tidemark, the six entrepreneurs below share one important thing: a unique perspective and way of seeing the world that only growing up on the outside can bring.

Christian Gheorghe: Romanian-born NYC limo driver turned founder and CEO of Tidemark

Christian Gheorghe, founder and CEO, Tidemark, who was previously the CTO and SVP at SAP, immigrated to the U.S. from communist Romania with a master’s degree in computer science and mechanical engineering. To make ends meet–and learn English at the same time–Gheorghe took a job in NYC as a limo driver. But this highly educated and hardworking immigrant didn’t let language barriers or low-skilled jobs set him back–they only motivated him.

“In retrospect, not knowing English when I first arrived at the modern version of Ellis Island–a brightly lit immigration room at JFK airport–was a blessing in disguise. Freedom, the first word I ever learned by listening to Pink Floyd records in communist Romania before escaping to America, was one of the few English words I did know and muttered to the immigration officer when he asked me, ‘Why are you here?’

“I learned later what great things an open and benevolent American immigration policy can really do for oppressed people such as myself. One thing is for sure: At that moment, as the wall was coming down, I was given a chance to be free. Freedom, as it turns out, has shaped everything in my life since I was allowed to immigrate to America.

“From learning how to drive a limo in NYC to make ends meet, to later writing software and starting companies to realize the vision I have for analytics for the many, a common thread emerges. The most amazing thing that America has given to me is the gift of freedom to build something from nothing, to find and work with teams of people that share common values, and to build and create value that matters,” says Gheorghe.

Iqram Magdon-Ismail: Zimbabwe-born, U.S. bred, cofounder of Venmo

Born in Zimbabwe to parents of Sri Lankan descent, Magdon-Ismail said his experience as an immigrant in the U.S. was very different from the experiences of his friends who immigrated to the U.S. and weren’t lucky enough to become citizens.

“I came to America when I was in the 7th grade. I feel very lucky to have become a U.S. citizen before I went to college–I was automatically granted citizenship when my mom became a citizen because I was under 18. Some of my friends in college didn’t have citizenship status, and I found myself planning my career differently. I didn’t require a special visa to stay and work in the U.S., whereas some of my college friends did. I knew after I graduated, the doors were wide open for me. I was free to explore, and start my own company. Some of my friends were dependent on company sponsorship in order to stay in the U.S. This seems like a good position for companies with enough wherewithal to sponsor students, yet still represents a minor inequality because the spectrum of companies I could work for versus some of my friends was slightly different.

“Venmo welcomes immigrants. They bring unique insight to our company because of their diverse experiences. I was immersed in a very different environment growing up and going to school in Zimbabwe. My immigrant perspective helps Venmo consider different markets, and a lot of the social encounters I had outside the U.S. continue to inspire some of the innovation you see in our product today. Nowadays, companies like Venmo can quickly reach global audiences. We want people from everywhere in the world to join our team.

“It would be nice if some of our immigration reform focused on helping international students pursue their dreams in America. I have met lots of bright students forced to leave the country because they didn’t have appropriate working status. America is the land of opportunity, and international students with lots of potential are like all other students that attend U.S. universities–we should do whatever we can to keep these amazing people here.”

Arianna Huffington: Greek-born, British-educated, American media maven

Arianna Huffington, the Greek-born entrepreneur and founder of The Huffington Post–which was sold to AOL for $315 million in 2011–brought with her the values her mother instilled in her when she was a young girl growing up in Greece as she immigrated to London and then the U.S., first moving to New York and later settling in California. The ambitious socialite turned political candidate turned businesswoman and media maven now runs one of the most influential and well-read publications in the U.S.–a publication that has an entire section dedicated to the topic of immigration.

“In the preamble to the Constitution, we are told that America is constantly moving toward a more perfect union, and the 40 million immigrants in the United States are a central part of that never-ending journey. Nowhere is that more evident than in our community of immigrant entrepreneurs.

“When I was growing up in Athens, my mother would tell me, ‘Failure isn’t the opposite of success; it’s a stepping stone to success,’ and when I came to America, I was given many opportunities to fail my way to eventual success. But my story is just one of millions. And it falls to all of us–especially those of us who have come here and started businesses–to do whatever we can to make sure the same opportunities we’ve enjoyed are there for the immigrants of today and tomorrow.”

Renaud Laplanche: French sailing champion turned founder and CEO of Lending Club

Renaud Laplanche, the French-born serial entrepreneur who in addition to founding two successful companies also happens to be a two-time French sailing champion and an Ernst & Young Entrepreneur of the Year, initially came to the U.S. as part of a one-year assignment with the New York law firm Cleary Gottlieb. But halfway into the assignment, the entrepreneur left the firm to found TripleHop Technologies, a leading software firm that was acquired by Oracle in 2005. But he didn’t stop there. In 2007, Laplanche founded Lending Club because his perspective of consumer credit growing up in France was vastly different than consumer credit in the U.S.–and he wanted to bring a friendlier credit model to his new home in America.

“My cultural background played a key role in the genesis of Lending Club. As an immigrant, I was not familiar with U.S. consumer credit and was shocked when I realized that credit card companies charge 18% interest rates. I was looking at this with a fresh pair of eyes because there is no such thing as credit cards in France, and consumer loans are a lot more affordable. I think most American consumers got used to the idea of paying high interest rates on credit cards, but for me it was something really new and that made me question the efficiency of the system and gave me the idea for Lending Club.”

Peter Weijmarshausen: Dutch founder of Shapeways

Dutch-born Peter Weijmarshausen founded Shapeways in 2007 within the Philips Electronics Lifestyle Incubator. Three years later, the immigrant entrepreneur left the incubator after securing venture funding for his 3-D printing marketplace, which is headquartered in New York. Now, Weijmarshausen is working to bring manufacturing back to the U.S., enabling a community where people can create, share, buy, and sell their own 3-D-printed designs.

“A company is nothing without its people and, as it stands, the freedom for employees to work wherever best suits them is not always supported by international immigration laws. Shapeways was started in the Netherlands and, after three years, we decided to move our headquarters to New York, which presented me immediately with the challenge of immigrating to the United States. We’re an international startup with a team still in the Netherlands and offices and a factory in New York. The team has roots from all over the world, and in the end we’ve managed to work within the bounds of the existing processes. But making them easier and more flexible will help Shapeways and other companies grow and compete in an increasingly global economy and internationally expansive workplace, both of which have been enabled by new information technologies.”

Phil Jaber: Founder of Philz Coffee

Phil Jaber, the founder of the hugely popular Bay Area-based Philz Coffee, says the values he grew up with in the Middle East are the same values that have led to his success in America. With 13 coffee shops spanning San Francisco and the Bay Area, Philz employs roughly 300 people and single-handedly fuels many of area’s entrepreneurs, startup founders, and tech giants from Facebook–which has a Philz coffee shop at headquarters–to Virgin America–which serves Philz coffee on its flights.

“I immigrated to the United States in the 1960s because I was looking for a better life. My older brother was already living in California and had opened his own business–so I moved out here and helped him around the shop. But from an early age, I knew I wanted to open my own business.

“Running a business isn’t just about the money. To be successful in business, you must really love what you do and you must treat people well–whether they’re your team members or your customers. My business is all about word of mouth–one person tells another person and quickly word spreads. So it’s important to treat each person the way you would want to be treated–after all, we all come from under the canopy of heaven.” Canopy of Heaven is coincidentally the name of one of the flavorful brews of coffee at Philz.

“Before opening my first shop, I visited more than 1,100 coffee shops to observe what worked and what didn’t work–I wanted to make sure that the culture and environment I was fostering at my coffee shop was a diverse, culture-rich, and welcoming one. From a young age growing up in Ramallah [on the West Bank], I learned how to live with and respect people of all cultures, and I wanted my coffee shops to reflect that. At Philz, we work to foster an environment that builds culture and community–an environment that helps people connect with each other.”

As I sat with Phil at his 24th Street location in New York, it was clear that his coffee shops were hubs of connection, collaboration, and diversity, as he pointed out a group of tech entrepreneurs drinking coffee during a brainstorming session, introduced me to a local doctor, and smiled looking at the young couple dancing in line to the café music.

“My heritage, culture, and family have played a big role in the way I run my shops,” Phil says, pulling out a laminated quote his father had written for him more than a decade ago that read: “Let the life I live speak for me.”

Let them in.

As Americans, we all have immigrant friends who have personally made our lives richer. And we’ve all heard their stories of going through the immigration process, of the lengthy and tiresome process of obtaining an H-1B visa and eventually becoming citizens. We’ve heard too many times their worried voices when discussing whether or not they’d be able to stay in the country if they wanted to quit their job and start their own business—the same risks we as citizens are encouraged to take–or what would happen if they got laid off and were out of a job for more than a month. Would they be sent back home?

As the daughter of parents who emigrated from Iran and started their lives in the U.S. from scratch, literally bringing with them only two suitcases and the clothes on their back, I understand too well how much hardworking and educated immigrants like my parents really want to be here, how hard they will work to succeed, and how much our country will benefit as a result of letting them in.

[Map of North America: Elena Elisseeva via Shutterstock]