Seventh-day Adventism is a fast-growing international Christian denomination of over eight million members. Its origins are in the interfaith Millerite movement of the 1840s. After the "Great Disappointment" of 1844 which marked the end of Miller's calculations of the date of Jesus' Second Coming, many left the movement. Those that remained--among them James and Ellen White and Joseph Bates--became convinced that Jesus had begun a special ministry in heaven. They remained expectant, however, for his soon return, as Adventists remain to this day. From humble New England beginnings in buggies and camp meetings, "adventists" carried out a strong literature and revivalist program which rapidly increased their numbers. Influence from Seventh-day Sabbath-keeping Baptists introduced that doctrine to the church, and Adventist acceptance of it has been an identifying mark ever since. The denomination was organized with its present name in 1863. Since 1874, when J. N. Andrews was sent as a missionary to Switzerland, Adventists have been increasingly active internationally. Presently, there are members on all inhabited continents, in over 200 countries. Adventist health ministries also started early, with the Battle Creek Sanitarium. Today the church operates hundreds of hospitals, clinics, aid centers, and medical training sites. Christian education has also been a key part of the Adventist experience. The first network of Adventist-sponsored schools was organized in 1872, and has grown to encompass elementary, secondary, tertiary, and post-graduate institutions.