The following material provides background on the 1914 chronology. The original calculations were mostly based on dates from John Aquila Brown, who in 1823 published a work claiming that the "seven times" of Daniel 4 were a period of 2520 years running from the beginning of Nebuchadnezzar's reign in 604 B.C. to 1917 A.D. While Brown never equated the 2520 years to the "Gentile Times," other writers soon did.1 Eventually Nelson H. Barbour picked up the torch and put the finishing touches on what became Charles Taze Russell's chronology. Barbour published his calculation of the Gentile Times for the first time in the September, 1875 issue of his monthly paper Herald of the Morning, starting them in 606 B.C. and ending them in 1914 A.D. In January, 1876 C. T. Russell read Barbour's paper, soon got together with him, and accepted all of Barbour's time calculations, even becoming a co-editor of Barbour's paper. These calculations included one that said Christ's presence began in 1874 and the "day of the Lord" began in 1873. Shortly thereafter, Russell published a similar calculation in the October, 1876 issue of The Bible Examiner. This paper was published by George Storrs, who was generally influential on Russell and had been a major leader in William Miller's movement. Storrs was active in Adventist related movements when Russell began publishing.
The earliest publications Russell was involved with stressed the urgency of the times, emphasizing that in 1874 Christ returned and by 1914 he would have destroyed all the kingdoms of the world. The 1877 book Three Worlds and the Harvest of This World, written by N. H. Barbour and financed by Russell, contained the basis for most of Russell's later chronology and many of his doctrines.
When did Christ's "presence" begin? Early Zion's Watch Towers said:
Christ came in the character of a Bridegroom in 1874.... at the beginning of the Gospel harvest. [October, 1879, p. 4]
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7 From that understanding of matters, the "chaste virgin" class began going forth to meet the heavenly Bridegroom in the year 1874, as they believed him to have arrived in that year and to be from then on invisibly present. They felt that they were already living in the invisible presence of the Bridegroom. Due to this fact, when Charles T. Russell began publishing his own religious magazine in July of 1879, he published it under the title "Zion’s Watch Tower and Herald of Christ’s Presence." He had already become familiar with Wilson’s TheEmphaticDiaglott, which translated the Greek word pa·rou·si as "presence," not "coming," in Matthew 24:3 and elsewhere. The new magazine was heralding Christ’s invisible presence as having begun in 1874. This presence was to continue until the end of the Gentile Times in 1914, when the Gentile nations would be destroyed and the remnant of the "chaste virgin" class would be glorified with their bridegroom in heaven by death and resurrection to life in the spirit. Thus the class pictured by the five wise virgins would enter through the door into the wedding.
The date of the close of that 'battle' is definitely marked in Scripture as October, 1914. It is already in progress, its beginning dating from October, 1874.
Zion's Watch Tower, 15 January 1892, page 1355
We see no reason for changing the figures--nor could we change them if we would. They are, we believe, God's dates, not ours. But bear in mind that the end of 1914 is not the date for the beginning, but for the end of the time of trouble.
Zion's Watch Tower, 15 July 1894, page 1677
The Scriptures show that the second presence [of the Lord] was due in 1874 . . . . This proof shows that the Lord has been present since 1874.
--The Watch Tower, 1 March 1923, page 67
Surely there is not the slightest room for doubt in the mind of a truly consecrated child of God that the Lord Jesus is present and has been since 1874.
--The Watch Tower, 1 January 1924, page 5
Russell later stated, "he had much to learn from me on the fulness of restitution based upon the sufficiency of the ransom given for all, as I had much to learn from him concerning time." Barbour succeeded in convincing Russell that Christ’s invisible presence had begun in 1874 .