Joseph Armstrong (1847-1907) was born in Carrollton, Illinois, and died in Boston, Massachusetts. He became interested in Christian Science in 1884 when his wife received Christian Science treatment from Silas J. Sawyer, a student of Mary Baker Eddy's. In 1886, he studied Christian Science with Janet T. Colman, a student of Mary Baker Eddy's. Afterwards, he studied with Mary Baker Eddy, taking Primary (1887), Obstetrics (1888), and Normal (1889) classes. Armstrong joined the Christian Scientist Association in December 1887 and joined The First Church of Christ, Scientist, on December 31, 1892. In 1892, after teaching and practicing in the Midwest, Armstrong and his wife, Mary E. Armstrong, moved to Boston, where he served on the Christian Science Board of Directors (1893-1907) and as publisher of the writings of Mary Baker Eddy (1896-1907).

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