Timeline

2001 - Betty Dukes, a Wal-Mart greeter at a store in Pittsburg, California, and five current or former female employees filed a lawsuit in federal court in San Francisco, accusing the retailer of discriminating against its female employees by paying them less than men and giving them fewer promotions.
2003 - Attorneys for the women filed a motion for class certification and asked the judge to rule the case can go to trial on behalf of all women who worked for Wal-Mart in the United States at any time since December 26, 1998, a group believed to exceed 1.5 million current and former female employees.
2004 - U.S. District Judge Martin Jenkins ruled the lawsuit can proceed as a nationwide class covering the women who worked at 3,400 stores, but did not decide the merits of the lawsuit. 2010 - A U.S. appeals court based in San Francisco, by a 6-5 vote, upheld the judge's conclusion that it would be better to handle the case as a single group rather than requiring individual lawsuits to be litigated.
2010 - Wal-Mart appealed to the Supreme Court. It argued claims involving current and former workers, hourly employees and salaried managers and stores across the country were too different to proceed as one class-action lawsuit. 2010 - The Supreme Court said it would decide whether the class-action certification violated federal rules for such lawsuits, one of the most important employment discrimination class-action cases in decades. 2011 - The Supreme Court heard one hour of arguments in the case by an attorney representing Wal-Mart and an attorney for the women. The justices, who sharply questioned both sides, then took the case under consideration.
2011 - The Supreme Court rejects class-action status for the female employees, accepting Wal-Mart's main argument that the women, in different jobs at 3,400 different stores nationwide and with different supervisors, do not have enough in common to be lumped together in a single lawsuit.

In 2000, Betty Dukes, a 54 year old greeter made claims of sex discrimination. She worked at Wal-Mart Stores for six year but was denied training that would allow her to receive a higher paying salary. In 2001, Ms. Dukes and other female employees filed a lawsuit against Wal-Mart Stores in California. The lawsuit filed was a class action sex discrimination lawsuit.
The lawsuit alleged that women were being discriminated against in its promotion and compensation acts. The women claimed to have received less pay than their male counterparts. They also claimed to receive fewer and less frequent opportunities than male workers at Wal-Mart Stores. The case eventually expanded to include more than one million women between 2003 and 2004. At that time, it was considered the largest class action lawsuit in United States history.
Charges were filed in every state except for Montana and Vermont. Florida, Alabama and Georgia carried the most claims. Current and former employees of Wal-Mart Stores requested a judgment against the company for injunctive and declaratory relief, punitive damages, and backpay, on behalf of themselves and the entire class.
It was proposed that the United States District Court for the Northern District of California include a class of women that were employed at Wal-Mart Stores since December 26, 1998. This would include women working at Wal-Mart and receiving less pay and find fewer and less frequent opportunities of promotion than the male workers. Wal-Mart objected to the massive size of the proposed class but the district court granted and approved the class.
Wal-Mart Stores did file an appeal, objecting to the class certification being valid. Wal-Mart Stores wanted the court to require that the employees file on an individual basis arguing that cases this size can be unmanageable . The court of the appeals ruled in favor of the employees on the class certification decision.
In 2004, a federal district judge ruled in favor of the class action lawsuit. This was a great victory for the employees but it was followed by appeals from Wal-Mart Stores.
The Supreme Court agreed to hear Wal-Mart Stores appeal in 2009. It was heard as an oral argument for the case on March 29, 2011. The Supreme Court ruled in favor of Wal-Mart Stores on June 20, 2011. It was determined that the plaintiffs did not have enough in common to constitute a class. The representatives of the female workers were very disappointed in the decision.
The ruling did not determine whether or not Wal-Mart Stores was guilty of sex discrimination. Companies have allowed discrimination based on sex for a long time. The case should have been on an individual basis or at least by separated by regions. This is very unfair to women employees that are being denied privileges based on their gender. Male privilege has been an issue that our country is working to solve. Women deserve equal rights.

References
Kearl, Holly. (October, 2012) Court Case: Wal-Mart Stores, Inc V. Dukes http://www.aauw.org/resource/wal-mart-stores-inc-v-dukes/ DeWeese, Natanya., Rumpf, James. (March 29, 2011) Supreme Court Collection
http://law.cornell.edu