William Miller

William Miller was converted from Deism sometime around or shortly after the end of the war of 1812--this occurred during the Second Great Awakening.
After conversion, Miller began to be a zealous Bible student.
By 1816 Miller had developed an intensive study plan---"I commenced with Genesis," Miller wrote, "and read verse by verse, proceeding no faster than the meaning of the several passages should be so unfolded, as to leave me free from embarrassment.....Whenever I found any thing obscure, my practice was to compare it with all collateral passages; and by the help of CRUDEN's Bible concordance, I examined all the texts of Scripture in which were found any of the prominent words contained in any obscure portion.  Then by letting every word have its proper bearing on the subject of the text, if my view of it harmonized with every collateral passage in the Bible, it ceased to be a difficulty." (A&D6---Apology and Defense, by William Miller)
For two years, (1816-1818) Miller studied his Bible intensively in this way.  Finally he came to "the solemn conclusion....that in about twenty-five years from that time {i.e., 1843} all the affairs of our present state would be wound up" and Christ would come (ibid. 12)  (2300day prophecy)
But he was also quite aware that his conclusion that Christ would return at the beginning of the millennium (1,000 years) of Rev. flew in the face of the almost universally accepted theology of his day, which held that Christ would return at the end of the millennium.  "I therefore," he penned, "feared to present it {his conclusion}, lest by some possibility I should be in error, and be the means of misleading any (ibid.13)
Because of his fears, Miller spent another five years (1818-1823) reexamining his Bible and raising every objection he could to his conclusions.  as a result he became more sure than ever that Christ would arrive about 1843.  So after seven years he began to speak of his beliefs openly to his neighbors.  However, he found only a "very few who listened with any interest"  (ibid. 15)
For nine years (1823-1832) Miller continued to study his Bible.  Meanwhile, he came increasingly under the conviction that he needed to share his findings of impending doom.  The impression "'Go and tell the world of their danger'" continually assailed him.  "I did all I could to avoid the conviction that any thing was required of me," Miller wrote.  But he could not escape his conscience (ibid. 15,16)
Taken from A Brief History of Seventh-day Adventists--Geo. Knight, (chapter, Millerite roots) by Dorothy Dunbar