Mary Baker Glover, as she then was, went to Portland in 1862 in poor health and was treated by Phineas Quimby, improved markedly, wrote to a newspaper praising him, and remained in contact until his death in 1866. Everything after that is contested.
Her own account places the discovery of Christian Science in 1866, when she recovered unexpectedly from injuries after a fall on ice while reading an account of a healing in Matthew, and holds that what she found was a revelation of divine Science that owed nothing to Quimby, whose method she came to regard as mesmerism and therefore as the opposite of her own. The Dresser family, and Quimby's son George, argued from the 1880s onward that she had taken his manuscripts and his ideas and renamed them, and the dispute ran through the courts and the press for decades.
The scholarly position today is neither of those. Historians generally accept a real debt in the early period, in vocabulary and in the basic conviction that illness is mental in origin, and also accept that what Eddy built diverges from Quimby in ways that matter: an explicitly theological metaphysics, an absolute idealism he did not hold, a scripture, and an institution he had no interest in. The atlas records the relation as debated, which is what it is, rather than adopting either camp's version.