Most powerful Women profiled on Women's Equality Day (2011 version) has rolled around yet again--celebrating 91 years of U.S. women's right to vote.

Women's Equality Day recognizes the passage of the 19th Amendment to the Constitution, which, after decades of struggle and heroism, gave more than half the population in this country the right to vote.

"The right of citizens of the United States to vote shall not be denied or abridged by the United States or by any state on account of sex," it reads. Yet, it was sex that chained women to second-class citizenry for centuries.

The first Women's Equality Day was in 1970, when three leaders of the women's movement -- Bella Abzug, Gloria Steinem and Betty Friedan -- got together and conspired to promote a women's strike for equality to celebrate the 50th anniversary of the passage of the 19th Amendment. Demonstrations were held in 90 major cities and 42 states. Read about more powerful women here. (c) tPC (c) UPI