The 19th amendment grants that "the right of the United States to vote shall not be denied or abridged by the Untied States or by any State on account of sex." Congress H.J.Res. I.
Source:
National Archives, http://www.archives.gov/historical-docs/document.html?doc=13&title.raw=19th%20Amendment%20to%20the%20U.S.%20Constitution:%20Women's%20Right%20to%20Vote
