Opening up your own company poses all sorts of obstacles, no matter your gender. But some women — in this country and overseas — encounter even more challenges depending on their community, education, competition and culture. Here are 15 female entrepreneurs from the past and present who are incredibly inspiring for their creativity, cleverness and courage.

1. Oprah Winfrey: Oprah’s been the queen of TV for decades, and while she’s moved on from her iconic talk show on network television, her Harpo Productions Inc. empire is still evolving. An entire cable network devoted to shows and people she finds inspiring is one of Oprah’s latest projects as she continues to build up her website, magazine and radio show. Born in a poor community in Mississippi, Winfrey was sent to live with different relatives around the country and was sexually abused as a child. She credits her father with "turning [her] life around" and helping her recognize her potential and her natural gifts, a mission she has pursued on her talk show and in her many charitable endeavors, like her Angel Network. Forbes calculated Winfrey’s net worth for 2011 at $2.7 billion.
2. Diane von Furstenberg: Fashion designer Diane von Furstenberg is known in the industry as a compassionate, modern mentor to young women, emerging talents, designers and Middle American fans. As a newlywed to the the German Prince Egon of Furstenberg, Diane vowed to start her own company and act as an independent woman instead of benefiting from her sudden luxurious lifestyle. Her wrap dresses became a major success among newly empowered American working women, and although she and her husband divorced — and she later suffered a major blow to business — von Furstenberg is again working and serving at the top of the fashion industry. As president of the Council of Fashion Designers of America, von Furstenberg mentors new designers. She also sits on the board of a women’s leadership organization called Vital Voices and promotes the efforts of other young women entrepreneurs, as well as the preservation of her local neighborhood in New York.
3. Madame C.J. Walker: In a speech given to the audience at the National Negro Business League Convention in 1912, inventor Madame C.J. Walker summarized her rise to business success by saying she was promoted from the cotton fields to the washtub to the cook kitchen — until she took her career and livelihood into her own hands by starting a manufacturing business. Born in Louisiana to former slaves, Walker was an orphan at six, a wife at 14, and a mother soon after. Inspired by a dream she’d had to start a cosmetics and hair-care line for African American women, Walker used the $1.25 she had saved to fund her new business. After selling her products door-to-door, Walker’s company eventually grew to serve customers around the world, making her the first self-made woman millionaire in the country.
4. Ashley Qualls: Qualls was just 14 when she started her own company, a website called Whateverlife.com that helped teens design their own MySpace pages and learn graphic design. Motivated to help other young people express their feelings and follow their own path in life, Qualls borrowed money from her mother to buy the domain name, but quickly recruited millions of visitors and earning tens of thousands of dollars per month. On her About page, Ashley reminds users that "no matter what your age is, never limit yourself!" and that when you find something you’re passionate about, you can take your "ideas to even higher heights."
5. Estee Lauder: One of the most famous female entrepreneurs in American history, Estee Lauder built an extremely successful business that’s still earning big profits today, despite the recession. Lauder was born in New York City to immigrant parents, but with the help of a chemist uncle, quickly began developing skin creams that were sold in clubs and resorts. Lauder eventually fought for her own counter space at Saks Fifth Avenue in Manhattan, gave samples to all of her friends and acquaintances, and expanded to fragrances in the next several years. Lauder became a billionaire before dying in 2004, and the Estee Lauder Companies shares are at this moment selling for $95.36 on the NYSE.
6. Mary Kay Ash: Another inspirational American entrepreneur is Mary Kay Ash, the woman who created Mary Kay cosmetics. The Texas native began her own business pursuits after resigning from a company that continued to promote male employees ahead of her, despite her seniority and higher skill set. She used her $5,000 in savings and the help of her son to start Beauty by Mary Kay — a company that now relies on 2 million beauty consultants to sell her products around the country.
7. Nellie Cashman: Cashman earned many nicknames during her life as a frontier woman, traveling between Western mining camps — Miner’s Angel, The Angel of Tombstone and Saint of the Sourdoughs are just a few. Irish-born Cashman moved to San Francisco from Boston with her sister in 1869 and first worked as a cook in mining camps until she could afford to open her own boarding house in Nevada, just three years later. For the next phase of her life, Cashman traveled around the North American West, opening restaurants and boarding houses while supporting the local communities through charitable projects with churches and the Salvation Army and giving out free cigars to her mining customers.
8. Caterina Fake: Modern-day entrepreneur Caterina Fake is the co-founder of Hunch and Flickr, but her influence reaches well beyond those two social sites. Fake has invested in many sites like Etsy, Maya’s Mom and Daily Booth, and serves on the board of Creative Commons. Through Hunch and Flickr, Fake is hoping to make the Internet a more personal and personally significant tool for broadening users’ perspectives and connecting us to the hobbies, people and causes important to them.
9. Kamila Sidiqi: In a country where women entrepreneurs aren’t just scarce, but extremely controversial and sometimes in danger of practicing their business, Kamila Sidiqi isn’t just quietly setting up her own shop. Instead, the dressmaker is helping other Afghan women develop their own companies, too. Left alone by a father and brother who fled the Taliban, Sidiqi helped her siblings, who in turn helped her start her business by teaching her to sew and taking her on potentially violent expeditions to buy supplies. Now, Sidiqi runs a consultancy firm supporting women entrepreneurs in her area.
10. Judi Henderson-Townsend: Henderson-Townsend recognized an opportunity for business and seized it — and her risk paid off. She bought up the entire inventory from a closing mannequin store and started a part-time business, called Mannequin Madness, which sells, rents, recycles, repairs and blogs about mannequins. The company has since become respected or its green and socially responsible business plan, helping other retailers recycle their mannequins instead of throwing them away.
11. Sara Blakely: Celebrities and everyday women often slip on a pair of SPANX products before a night out — or important meeting — to help them feel more comfortable and confident in their clothing. Started by Sara Blakeley, the SPANX line of slimming apparel and undergarments is a relatively new company but has beam an indispensable product for women around the country. Blakeley worked hard to maximize her savings to start her company, reading books on getting trademarked, driving around to convince manufactures to make her products, and even using inspiration from her background in stand-up comedy for branding purpose, and inviting sales reps from distinguished department stores into the fitting room to prove how well her SPANX worked. Oprah came calling soon after.
12. Ishita Khanna: This young entrepreneur is dedicated to helping remote Himalayan villages go green in an effort to boost their economy and become more sustainable. She has educated and motivated the community in environmental management through her company Spitiecosphere, which focuses on eco-travel, organic crops and conservation as its principle projects.
13. Lauren Bush: Although she’s former President George W. Bush’s niece and fiance to Ralph Lauren heir and executive David Lauren (yes, she will be Lauren Lauren), and once worked as a model, Lauren Bush was motivated enough to start her own sustainable company just after graduating college. As the co-founder of FEED, and Chairman of the Board of the FEED Foundation, Bush worked with the UN to start a company that facilitates the creation of bags and accessories that are sold to raise donations to help feed underserved populations around the world. Each FEED product is made from environmentally sound materials, using fair-labor production and artisan-made materials.
14. Ama Pomaa Andoh: Ama Pomaa Andoh is the founder of Ghana Young Women Social Entrepreneurs, a resource center for women who want to learn how to start their own business. Women are encouraged to implement "innovative grassroots change" that is sustainable and mutually beneficial to their communities. After a meeting at the FORTUNE/U.S. State Department Global Women’s Mentoring Partnership organized by Diane von Furstenberg-supported Vital Voices, Ama Pomaa Andoh returned home to start GYWSE.
15. Deborah Meaden: Meaden dropped out of high school to take business classes at a technical school, and moved to Italy after graduation. She quickly developed her own glass and ceramics import company, which was successful at first but ended up cheating her out of business. Meaden moved on to other projects before buying out an existing business and taking over. Today, Meaden is a successful investor and marketer in the UK.