[4] Even though the family were Quakers, three of her brothers, Morris, Francis and Lewis, fought in the Civil War for the Union Army.

[1][13] Mary, her mother, and her niece Harrier were members of the Paris, France chapter of the Daughters of the American Revolution.

[17] Hallowell traveled to European art centers to arrange for works of art for the Inter-State Industrial Expositions in Chicago[10] and worked with William Merritt Chase, James McNeill Whistler, John Singer Sargent, and other Barbizon and European schooled artists.

She popularized Impressionist art in the city with exhibition of the works of Degas, Monet, Pissarrol[16] Alfred Sisley, and Pierre-Auguste Renoir in the 1890 Inter-State show.

Carolyn Kinder Carr, author of Sara T. Hallowell: Forsaking Plain for Fancy, stated that she was the first woman in exhibition management.

[10] Hallowell was one of the agents[18] and then assistant director of the Department of Fine Arts for the World's Columbian Exposition of 1893 in Chicago.

Author Carolyn Kinder Carr said, "As newspaper accounts of the day made clear, her gender rendered her ineligible for this high-profile job.

"[19] Hallowell was responsible for collecting 19th-century European art and identifying candidates for painting of wall murals by women artists.

[20] Hallowell, who met Rodin in the early 1890s when arranging for art works for the exposition, was to become his "best American friend" in the 19th century.

[19][23] She returned to the United States to "keep in touch with America's wonderful school of landscape painters" in Chicago, Philadelphia, Pittsburgh, Boston and New York.

She also included the works of French artists, like Rodin and Robert Henri, in those she personally selected and sent to the Art Institute.

[19] Sarah and her niece Harriet lived in Moret during World War I and volunteered at the local hospital.