Answer:
Mary Edwards Walker died of natural causes on February 21, 1919 at the age of 86. If she died for anything, then it would have to be women's suffrage, as she was an active participant in the women's rights movement along with others leaders like Elizabeth Cady Stanton and Susan B. Anthony. She died just a year prior to the passage of the Nineteenth Amendment to the US Constitution which granted women the right to vote.