She was born in 1878 to parents who were both baptized German Baptist Brethren. Mattie was baptized at age 16. After graduating from high school and inspite of strong opposition of her father, she enrolled at Manchester College in 1900. She and her brother Joe cooked and ate their meals off campus during the first year because of prejudice. In the second year, however, fellow student Otho Winger organized a group which supported Mattie and Joe and made them feel welcome in the college dining rooms.
After graduating in 1903, Mattie joined an effort sponsored by the General Mission Board to start a new church among the Afro-American people in Palestine, Arkansas. After the first year, death resulted in her alone providing leadership to the new church. She worked tirelessly to organize a Sunday School and to raise funds for a new church building. However, it was malaria and ill health which forced her to leave this ministry in 1906 and move to Southern Ohio to work among several black congregations there. It was there she was elected to the ministry and installed in a ceremony December 30, 1911. She also met and married Newton Dolby in 1907.
A family move to Urbana, Illinos eventually resulted in Mattie's ministry being lost to the Brethren. They commuted 24-miles round trip each week for 7 years to attend a Brethren congregation until after a change of administration they were made to feel unwelcome and Mattie eventually served a Methodist Church as a minister for nine years.
Source: Planting the Faith in a New Land