In what year was the Church of Christ, Scientist founded?

The Church of Christ, Scientist, was founded in 1879 by Mary Baker Eddy. This year is significant because it marks the establishment of the church after Eddy's development of Christian Science, which began with her study of the healing practices and spiritual insights that influenced her work. The formation of the church in 1879 was a pivotal moment, as it not only formalized her teachings but also established a community dedicated to the practice of Christian Science and its principles, focusing on spiritual healing and understanding of the divine.

The other years mentioned do not align with the founding of the Church. For instance, 1865 predates the significant developments in Eddy's religious teachings, while 1885 and 1900 came after the church was already established and had started to grow. Thus, 1879 is the accurate and historical year associated with the founding of the Church of Christ, Scientist.