The historian Walter LaFeber wrote that the decades after the Civil War marked the beginning of modern American diplomacy. The dominance of northern and western economic interests, America's expansionist ideology, and the nation's growing industrial might made the United States a truly global power during this period. In the Philippines, Midway Islands, Hawaii, and Alaska the nation formed in a struggle for independence became, despite significant domestic opposition, a colonial overseer. The United States built an imperium that soon rivaled the empires of old.
The American empire was not only "new" in its chronology, according to LaFeber. It was also "new" in its structure and governing ideology. This was an empire predicated on the assumption that all of the world could become like the United States. William Henry Seward, secretary of state from 1861 to 1869, envisioned an almost unlimited expanse of liberty and enterprise. Railroads, ships, and other government-sponsored projects would allow for the free movement of people and products. Education and the rule of law would protect the freedom of the individual and the property of the merchant. Most importantly, Seward believed that America's model of a democratic society would improve the lives of citizens across the globe, even if it required violence and repression in the short run. This was a revolutionary vision that, like others, required sacrifice (usually most burdensome for non-Americans) on behalf of a higher cause. Democracy and markets were the perceived wave of the future, uprooting traditional hierarchies in Europe, Asia, Latin America, and other continents.
Seward's revolutionary vision served America's material and strategic interests, but it also had sincere racial and religious roots. Belief in an Anglo-Saxon mission to "Christianize" the world came through in one of the most widely read books of the post–Civil War years: the Reverend Josiah Strong's Our Country. Published in 1886 on behalf of the American Home Missionary Society, the first edition sold more than 130,000 copies (an astronomical figure for the time) and was serialized in countless newspapers. Like Seward, Strong affirmed the importance of expanded American influence throughout the world. Industrialization had brought the world closer together, Strong argued. Nations had to prepare for more intense international competition. Strong affirmed Seward's vision of a democratic and market-driven empire. He also elaborated on the importance of this imperial turn for America's "Anglo-Saxon Christian mission." In language that appealed to the prejudices of many readers, Strong asserted: "There is no doubt that the Anglo-Saxon is to exercise the commanding influence in the world's future."
Struggling as he saw it against "heathen" influences in Asia and other parts of the globe, Strong assured readers that "I cannot think our civilization will perish…. I believe it is fully in the hands of the Christians of the United States, during the next ten or fifteen years, to hasten or retard the coming of Christ's kingdom in the world by hundreds, and perhaps thousands, of years." For Strong and his many thousands of followers, the Anglo-Saxon "race" was uniquely suited to bring civilization to the rest of the world. Our Country contained extended "scientific" discussion about the superiority of Anglo-Saxon physiques, the adaptability of settlers from this stock, and, most importantly, the positive influence of Protestantism. Free from the oppression of a Roman Catholic Church, an emperor, or any superstitious deities, Anglo-Saxons developed unique qualities of liberty and enterprise. They were self-governing and capable of creative production, according to Strong. Our Country tapped into popular anxieties that the growth of competing empires, the migration of "inferior races," and the spread of industrialization in the second half of the nineteenth century threatened Anglo-Saxon virtues. In this context Strong wrote that "the destinies of mankind, for centuries to come, can be seriously affected, much less determined, by the men of this generation in the United States." A global American empire would protect the essential qualities of Anglo-Saxon civilization by remaking the rest of the world in the U.S. image. Racial characteristics were inherited, according to Strong, but they could be overcome by the socializing qualities of Christian doctrine. Converted believers in far-off lands could receive grace from God. American expansion and colonization in places like Hawaii and the Philippines promised, in Strong's words, to "mold the destinies of unborn millions."
This was God's revolution on an international scale. Strong's words reflected a popular American disposition to dislodge "heathen" elites overseas. Businessmen claimed they were doing God's work when they seized local resources and established trading posts in formerly closed societies. Missionaries asserted divine sanction when they disregarded local traditions and proselytized their beliefs to native citizens. Most significantly, U.S. military forces in Asia, Latin America, and other areas argued that violence was a necessary means of building God's kingdom. Citing Charles Darwin on the "survival of the fittest," Strong claimed that resisting populations would be routed in a contest "of vitality and of civilization." As on the western frontier in earlier years, after the Civil War Americans built an extensive new empire, employing brutality for the sake of revolutionary ends.