The successful event, which attracted 2,000 participants, lead to their establishing a weekly prayer group at their home and marked the beginning of Rhoda's philanthropic career.

Under her leadership as president, the association's activities included sponsoring weekly prayer gatherings, distributing religious tracts, organizing Sunday schools, and visiting jails, but its major accomplishment, which occurred in 1868, was the establishment of a Home for Friendless Women in Richmond.

[8] On January 11, 1867, Indiana governor Oliver P. Morton, a childhood friend of Charles Coffin, appointed him to a commission tasked with investigating the need for a reformatory for boys.

Based on the commission's findings, the state government established the House of Refuge for Juvenile Defenders, a reformatory school for boys in Plainfield, Indiana.

"[14] The Coffins spent months lobbying members of the Indiana General Assembly to support legislation to establish a women's prison and on May 13, 1869, the bill was approved.

[14][15] Coffin's success in securing a separate prison facility for women in Indiana and advocating for the rehabilitation of female inmates made her a well-known figure in the prison-reform movement.

Recognized as an expert on the subject and for her role as the founder and board president of Indiana's pioneering women's prison, Coffin also wrote articles and made conference presentations on the topic.

In addition, opposition to her leadership of the Indiana’s women’s prison board caused her to resign her position as its president in 1881 after controversies and inmate complaints about mistreatment.

In November 1874, after the movement attracted strong local opposition, Coffin and other Richmond women established a chapter of the WCTU, a "more traditionally-structured temperance organization" to further their reform efforts.

[20] Coffin's work on behalf of female prisoners and the legislative battles that ensued also led to her recognize the need for women's equality and political rights.

After Coffin met with Governor Albert G. Porter, he eventually recommended the candidate the reform-mined group preferred and Doctor Sarah Stockton joined the asylum's staff.

While her husband reported his observations to Governor Porter and religious publication, Coffin provided the Indiana mental hospital with supplies and items to amuse its female patients.

The bank failure caused the Coffins to lose much of their wealth and the scandal overshadowed the couple's prior accomplishments and limited their impact on future reform efforts.

It is not clear whether Rhoda knew the details of the bank's poor management practices prior to its failure, but many members of the community found her guilty by association.

However, she gained a national reputation for her efforts to successfully establish the Indiana Reformatory Institution for Women and Girls, the country's first female-controlled prison, and also served as president of its board of managers.

Her lifelong interest in charitable work and social reform led to her assistance in securing the appointment of the first female physician to the staff of the Indiana Hospital for the Insane.

After a bank scandal involving her husband and sons forced the Coffins to move to Chicago in 1884, Rhoda continued to advocate for prison reform, women's rights, and other causes.

Carole D. Spencer argues that Coffin's work represents "a feminist's fight for women's rights in a male-dominated society," while Thomas D. Hamm considers her involvement in the Quaker renewal movement as a behind-the-scenes effort in partnership with her husband.

Hamm maintains that Coffin was "content to remain in the socially acceptable and subordinate roles" that the more radical Quaker women reformers had rejected.