The Bible Student movement is a Millennialist Restorationist Christian movement. It emerged from the teachings and ministry of Charles Taze Russell (1852–1916), also known as Pastor Russell, and his founding of the Zion's Watch Tower Tract Society in 1881. Members of the movement have variously referred to themselves as Bible Students, International Bible Students, Associated Bible Students, or Independent Bible Students. A number of schisms developed within the congregations of Bible Students associated with the Watch Tower Society between 1909 and 1932. The most significant split began in 1917 following the election of Joseph Franklin Rutherford as president of the Watch Tower Society two months after Russell's death. The schism began with Rutherford's controversial replacement of four of the Society's board of directors and publication of The Finished Mystery in July 1917. Thousands of members left congregations of Bible Students associated with the Watch Tower Society during the 1920s, prompted in part by Rutherford's failed predictions for the year 1925, increasing disillusionment with his on-going doctrinal and organizational changes, and his campaign for centralized control of the movement. William Schnell, author and former Jehovah's Witness, claims that three quarters of the original Bible Students who had been associating with the Watch Tower Society in 1919 had left by 1931. In 1930 Rutherford stated that "the total number of those who have withdrawn from the Society... is comparatively large." Between 1918 and 1929, several factions formed their own independent groups, including the Stand Fast Movement, the Pastoral Bible Institute, the Laymen's Home Missionary Movement founded by PSL Johnson, and the Dawn Bible Students Association. These groups range from conservative (claiming to be Russell's true followers) to more liberal (claiming that Russell's role is not as important as once believed). Rutherford's faction of the movement retained control of the Watch Tower Society and adopted the name Jehovah's witnesses in July 1931. By the end of the 20th century, Jehovah's Witnesses claimed a membership of 6 million, while other independent Bible Student groups had an estimated total of less than 75,000. Foundation In 1869, Charles Russell viewed a presentation by Advent Christian preacher Jonas Wendell (influenced by the Millerites) and soon after began attending an Adventist Bible study group in Allegheny, Pennsylvania led by George Stetson. Russell acknowledged the influence of Adventist ministers including George Storrs, an old acquaintance of William Miller and semi-regular attendee at the Bible study group in Allegheny. In