In the 19th century the association of the millennium with the role of the United States in history proved to be a volatile mixture in the hands of Protestant ministers, and for much of that period millennialism fed the fires of nationalism and Manifest Destiny. In a typical utterance, a leading Presbyterian minister of the 1840s, Samuel H. Cox, told an English audience that "in America, the state of society is without parallel in universal history.…I really believe that God has got America within anchorage, and that upon that arena, He intends to display his prodigies for the millennium." The Social Gospel movement of the late 19th century demonstrated most clearly the continuing influence of progressive millennialism.

The advocates of optimistic millennialism were confident of their ultimate triumph but did not take evil lightly. God’s kingdom would advance, they argued, but not without difficulty. Although they were not apocalyptic, their view of history included the cataclysmic. During the American Civil War, for example, in “The Battle Hymn of the Republic” antislavery writer Julia Ward Howe described God’s truth as "marching on” and “trampling out the vintage where the grapes of wrath are stored." The same idea is central to President Woodrow Wilson’s crusade to make the world "safe for democracy" through the entry of the United States into World War I. According to the progressive millennialists, Christ’s Second Advent would occur at the close of the millennium as its crowning event, and, as a result, their position has been called postmillennialism.

By accepting the progress of science, however, progressive millennialism-postmillennialism “watered down” its commitment to the Bible. Theories of geologic and biological evolution—which called into question the validity of the Bible’s account of creation—further weakened the biblical foundation of postmillennialism. Scientific progress also called into question chronological millennialism, which, since Anglican Bishop James Ussher’s work in the 17th century, had identified Jesus’ birth as 4004 am and therefore expected the sabbatical millennium to occur at the end of the second Christian millennium, in 2000.

In response to the dilution of biblical postmillennialism, English and American Protestants, led by the 19th-century theologian John Nelson Darby and the Plymouth Brethren, elaborated a series of “dispensations,” or periods of time during which God interacts with humanity according to an evolving set of rules. The most recent dispensation, they believed, had begun in the aftermath of the Crucifixion and would end with the Rapture, that moment when God bodily “takes up” his chosen before visiting upon the world his long-withheld wrath—the seven-year Tribulation described in Revelation—during which the Antichrist would come to tempt, if possible, even the saints. The Battle of Armageddon would follow, resulting in the victory of the celestial forces, the return of Jesus (Parousia), and the establishment of the millennial kingdom.

This premillennialism avoids political involvement by asserting that the world is too pervaded with evil to carry out, even with divine guidance, a plan for the millennial kingdom on earth. Only divinely wrought catastrophe and the direct intervention of Jesus could bring the victory of God’s truth. As a result, premillennial dispensationalism rejects progress as a snare of the Devil and calls for a return to the fundamentals of true religion, belief in the inerrancy of scripture, and the necessity of believers to maintain their faith and morals. Premillennialists await the catastrophic hand of God and seek to win as many people to the side of the Lord before the Rapture as they can.

In a sense, premillennialism and postmillennialism have coexisted since the earliest church, each succeeding the other in the aftermath of its disappointed apocalyptic hopes. Thus, after the triumph of postmillennialism in the mid-19th century, premillennialism came to the fore at the end of the century. The rise of postmillennial optimism in the activist Christian movements of the early 20th century (e.g., Prohibition and suffrage) brought about a wave of millennialism in the wake of World War I.

Influences on modern ideologies

Western civilization, even in its modern secularized forms, is heir to a long tradition of Christian thought. Thus, it is not surprising that many social reform movements as well as utopian ideologies bear traces of Christian influence. Enlightenment and Romantic thinkers proposed ideas of human progress toward peace and harmony that reveal messianic-millenarian origins. The 18th-century German philosopher Immanuel Kant described the ideal state of eternal peace as a "philosophical chiliasm." The debt of presocialist utopian thinkers—such as Henri de Saint-Simon, Robert Owen, and Charles Fourier—to Christian millenarianism was recognized by Karl Marx and Friedrich Engels, who, in their Communist Manifesto (1848), contemptuously referred to the utopias of these writers as "duodecimo editions of the New Jerusalem." Some early socialist movements exhibited messianic features, and Marxist communism has a markedly messianic structure and message. In describing some of the similarities between Marxism and traditional Christian eschatology, the English philosopher Bertrand Russell noted, ironically, that Marx adapted the Jewish messianic pattern of history to socialism in the same way that the philosopher-theologian Augustine adapted it to Christianity. According to Russell, the Marxist materialist dialectic that governs historical development corresponds to the biblical God, the proletariat to the elect, the Communist Party to the church, the revolution to the Second Coming, and the communist commonwealth to the millennium.