Final answer:
Mercy Otis Warren challenged traditional gender roles during the Revolutionary War by publishing anti-British works and a notable three-volume history of the revolution after her husband went to war.
Step-by-step explanation:
While her husband was away fighting in the Revolutionary War, Mercy Otis Warren became an early advocate for women's rights and played an active role in opposing British reform measures. After her husband's departure, she took a bold step beyond the domestic sphere women were traditionally confined to by engaging in public life and publishing anti-British works.
Her most notable contribution was the three-volume History of the Revolution, which she began in the late 1770s and published in 1812, marking her as a significant figure in the documentation of American independence.