During the Civil War, she volunteered as a leading member of the United States Sanitary Commission. As architect of its Northwestern branch, she attended a council of the national sanitary commission at Washington in December 1862, organized and communicated to thousands of women in hundreds of Ladies Aid Societies.  She spent time visiting army posts and inspecting hospitals. Under her guidance, the Chicago Branch of the USSC worked to send food, clothing and medical supplies to soldiers in the field.    

 

    Mary had a strong relationship with Mother Bickerdyke and her Chicago home was often a haven for the weary Bickerdyke.  There, Bickerdyke would convalesce to regain strength.  Mary often followed Mother Bickerdyke into field hospitals to give her a hand in organization.  Livermore's Chicago Branch assisted the wounded after some of the war's most deadly battles, including the bloody battle at Shiloh, Tennessee.

   

    The doctors and inspectors of the Sanitary Commission were men. But the local chapters of the organization were solely made up of women like Mary Livermore. Among their other duties, these women collected blankets, food, and clothing and assembled them into care packages, trying to provide a "box a month for the soldiers." The organization and delivery of the large amount of these items was accomplished by  women who were branch leaders.

 

   The women of the Sanitary Commission also raised large sums of money to support their efforts of providing for their troops.  These funds would be used to purchase things the women could not make themselves. They organized fundraising fairs that lasted for weeks and produced thousands of dollars for supplies for the soldiers. Mary Livermore was the chief organizer of the North-Western Sanitary Fair in October 1863. This event in Chicago raised $86,000 (worth 1.54 million in 2010). President Lincoln donated his own copy of the Emancipation Proclamation, which was auctioned off at $10,000.

 

    Mary's work on the Sanitary Commission convinced her that in order for social reforms to take place, women needed the right to vote. Learning much from the leadership she exercised during the war, she provided guidance and energy to women's organizations including the American Woman Suffrage Association and the Woman's Christian Temperance Union. She served as president of the AWSA group from 1875 to 1878. She also wrote for numerous reform periodicals and spoke on behalf of liberal causes all over the country.  Livermore’s memoirs, My Story of the War, still stands today as a testament of women’s determination and devotion. Her death in 1905 marked an end to a long and fruitful career of public service.