Merrill resigned the professorship in 1883, but continued to offer private instruction at her home until shortly before her death.

Her father, a native of Vermont who attended Dartmouth College, was an early leading citizen of Indiana.

[12] Shortly after the outbreak of the American Civil War, the two women returned to the United States.

[13] Merrill pursued a lifelong career as an educator, but she also served as a nurse during the American Civil War.

As the school's enrollment increased, it moved to the basement of the Fourth Presbyterian Church at Market and Delaware Streets.

[11][14] In June 1861, Merrill sailed to the United States after an extended stay in Europe, arriving in Indianapolis on July 5, 1861.

By the war's end in 1865, she had returned to Indianapolis to resume teaching at her school, which other local women had run for Merrill during her absence.

[18] Merrill accepted the appointment on April 21, 1869, and began teaching at Butler's campus on Indianapolis's near northside in the 1869–70 academic year.

Merrill became the second female university professor in the country, preceded by Maria Mitchell at Vassar College the previous year.

"[22] In 1875, when the university moved to a new site in the suburban community of Irvington and changed its name to Butler, Merrill initially commuted to Irvington from her home in Indianapolis, but took up temporary residence in homes closer to the campus after the journey proved too time-consuming.

[27][28] Well known and respected in academia and in the city's social circles, Merrill was active in civic groups, delivered public lectures, and served on various committees.

[9] Following her retirement from Butler University in 1883, Merrill continued to teach literature, offering private lessons at her home.

Merrill's long life and career as an educator, nurse, and college professor, opened doors for other women.