Throughout 2011, Working Mother has been highlighting the accomplishments of the most powerful moms in the country—from Washington lawmakers to pop-culture icons. To conclude the year we have assembled the most powerful moms from the year to highlight. The women selected have at least one child who is 18 years old or younger, reside in the U.S. and are major power players whose accomplishments are also societal contributions. But who is the most powerful?

See the complete list and profiles of the Most Powerful Moms of 2011 here.

Tennis superstar and mom of one, Kim Clijsters, is our Most Powerful Athlete Mom. Clijsters has been at the top of her game for years, but in 2011 she became the first mom to hold the number one spot in singles in the World Tennis Association. It was significant, not just for Clijsters, but for all working-mom athletes striving to prove that motherhood doesn’t take them out of the game. 

2011 was also a banner year for NBC Today show’s Ann Curry, our Most Powerful Mom on TV. After 14-years at Today, Curry was promoted to co-anchor of the program, following in the footsteps of another mom, Meredith Vieira, who left to spend more time with her family. Few women have as much visibility on television as Curry, who has made a name for herself as a serious journalist, often filing stories from international hot zones like Afghanistan and landing exclusive interviews with the likes of General Tommy Franks.

As co-chair of the Bill & Melinda Gates Foundation, our Most Powerful Mom in Nonprofits, Melinda Gates, helped to give away $3 billion in 2011 to causes that support global health and education. She also began to focus her attention on family planning. “Over the past several years, I have learned that small investments in family planning pay huge dividends for women, their families, and whole nations,” said Gates at the International Conference on Family Planning. The foundation she co-founded with her husband, now the largest philanthropic organization in the world, controls a whopping $33.5 billion endowment.

For others on our list, 2011 has been notable for personal reasons. Most Powerful Mom in Pop Culture actress and comedian Tina Fey gave birth to her second daughter, Penelope, and a bestselling biography entitled Bossypants. Cementing her place in Hollywood, Fey also received a star on The Hollywood Walk of Fame.  

Two pairs of partners proved women working together can bring innovation to the table and turn it into a successful business. BlogHer founders Lisa Stone and new-mom Jory Des Jardins continue to grow their brand based on the premise that women blog. They are undoubtedly this year's Most Powerful Moms in Social Media. Another pair who have made their mark in the Internet are the shopping revolutionaries and Gilt Groupe founders Alexis Maybank and Alexandra Wilkis Wilson. They are 2011's Most Powerful Mom Entrepreneurs.

Mary Schapiro, the chairman of the U.S. Securities and Exchange Commission (SEC), is our Most Powerful Mom in Finance and Banking. Other moms featured on that list have not been immune to the turbulence in the financial sector. Sallie Krawcheck was forced out of her role at Bank of America, where she ran two of its wealth management units. Alluding to this, Krawcheck said at the Securities Industry and Financial Markets Association annual meeting, “I wanted to apologize to young women at Harvard at a recent talk for not having gone far enough in 25 plus years.” Barbara Desoer, President of the Home Loans Division at Bank of America, was demoted not once, but twice this year. If anyone has the capacity to bounce back in 2012 though, it’s a working mom. 

One of our Most Powerful Moms in Social Media duo, BlogHer co-founder Lisa Stone, told us that balancing work and family is certainly a struggle, but one with many rewards. "To balance work and home, I’ve cut many things out of my life," she said. "If I allowed myself to look at the cup half empty, I’d wail over the time I don’t have to see friends or sew or paint or read or ski. But what I do get is my family and my work, both of which I’m in love with; and both get 100 percent of my commitment.”

In 2010, Working Mother selected Sheryl Sandberg, the COO of Facebook, as the Most Powerful Mom of the Year because of her role in changing the way that the world consumes media. This year we want to hear from you as we assess who should be the Most Powerful Mom of 2011. Should it be First Lady Michelle Obama because of her commitment to fighting childhood obesity, Gilt Groupe co-founders Alexandra Wilkis Wilson and Alexis Maybank for changing the way we shop, or another one of our Most Powerful Moms? Read the complete list here and weigh in on our Facebook page or via Twitter @_workingmother_ using the hashtag #mpm2011.

NEW: Listen to workingmother.com Editor Helen Jonsen talk about 2011's Most Powerful Moms on NPR's "Tell Me More."