Born and raised in Brooklyn, New York, she grew up in a wealthy family. She graduated from Vassar College 1909. In July 1913, she married Eugen Jan Boissevain, a Dutch importer.
She led the Suffrage Parade in Washington, DC, on the day of Woodrow Wilson's inauguration, March 13, 1913, draped in white robes and riding a huge white horse.
In 1916, she went on a speaking tour in the West, despite suffering from pernicious anemia. During a speech in Los Angeles that September she suddenly collapsed. Ten weeks later, on November 25, 1916, she died at the age of 30. Her last public words were, "Mr. President, how long must women wait for liberty?"
Several years after her death, Eugene Jan Boissevain married Edna St. Vincent Millay.