According to Amnesty International

The Convention on the Elimination of All Forms of Discrimination Against Women (CEDAW, or the Treaty for the Rights of Women), was adopted by the United Nations in 1979, and is the most comprehensive international agreement on the basic human rights of women. The Treaty provides an international standard for protecting and promoting women's human rights and is often referred to as a "Bill of Rights" for women. It is the only international instrument that comprehensively addresses women's rights within political, civil, cultural, economic, and social life.

As of October, 2002, 170 countries had ratified CEDAW. The United States is among a small minority of countries that have not yet ratified CEDAW, including Afghanistan, Iran, and Sudan. The United States has the dubious distinction of being the only country in the Western Hemisphere and the only industrialized democracy that has not ratified this treaty.

The Senate Foreign Relations Committee voted in July 2002 to recommend ratification of CEDAW, but the Treaty has never come before the full Senate for a vote. Ratification of the Treaty requires the support of 2/3 of the US Senate, or 67 votes.

http://www.amnestyusa.org/violence-against-women/ratify-the-treaty-for-the-rights-of-women-cedaw/page.do?id=1108216