The Anti-Imperialist League was formed in the United States against the annexation of the Philippines. Among the writers of that time was Mark Twain, vice president of the League from 1901 until his death in 1910. Mark Twain wrote an essay entitled To the Person Sitting in Darkness. published by the North American Review in February 1901. This essay sparked a nationwide controversy and Mark Twain as one newspaper said “has suddenly become the most influential anti-imperialist and the most dreaded critic of the sacrosanct person in the White House....”

Source: Twain, Mark. To the Person Sitting in Darkness. North American
Review 172 (Feb 1901).
http://www.accinet.net/~fjzwick/twain/persit.html In Jim Zwick, ed., Anti-Imperialism in the United States, 1898-1935. http://www.accinet net/~fjzwick/ail98-35.html (December 12, 1996).

Here’s an excerpt from Twain’s essay, To the Person Sitting in Darkness:

Our case is simple. On the 1st of May, Dewey destroyed the Spanish fleet. This left the Archipelago in the hands of its proper and rightful owners, the Filipino nation. Their army numbered 30,000 men, and they were competent to whip out or starve out the little Spanish garrison; then the people could set up a government of their own devising. Our traditions required that Dewey should now set up his warning sign, and go away. But the Master of the Game happened to think of another plan—the European plan. He acted upon it. This was, to send out an army—ostensibly to help the native patriots put the finishing touch upon their long and plucky struggle for independence, but really to take their land away from them and keep it. That is, in the interest of Progress and Civilization. The plan developed, stage by stage, and quite satisfactorily. We entered into a military alliance with the trusting Filipinos, and they hemmed in Manila on the land side, and by their valuable help the place, with its garrison of 8,000 or 10,000 Spaniards, was captured—a thing which we could not have accomplished unaided at that time. We got their help—by ingenuity. We knew they were fighting for their independence, and that they had been at it for two years. We knew they supposed that we also were fighting in their worthy cause—just as we had helped the Cubans fight for Cuban independence—and we allowed them to go on thinking so. Until Manila was ours and we could get along without them. Then we showed our hand. Of course, they were surprised—that was natural; surprised and disappointed; disappointed and grieved. To them it looked un-American; uncharacteristic; foreign to our established traditions. And this was natural, too; for we were only playing the American Game in public—in private it was European. It was neatly done, very neatly, and it bewildered them. They could not understand it; for we had been so friendly—so affectionate, even—with those simple-minded patriots! We, our own selves, had brought back out of exile their leader, their hero, their hope, their Washington —Aguinaldo; brought him in a warship, in high honor, under the sacred shelter and hospitality of the flag; brought him back and restored him to his people, and got their moving and eloquent gratitude for it. Yes, we had been so friendly to them, and had heartened them up so many ways!

We had lent them guns and ammunition; advised with them; exchanged pleasant courtesies with them; placed our sick and wounded in their kindly care; entrusted our Spanish prisoners to their humane and honest hands; fought shoulder to shoulder with them against “the common enemy” (our own phrase); praised their courage, praised their gallantry, praised their mercifulness, praised their fine and honorable conduct; borrowed their trenches, borrowed strong positions which they had previously captured from the Spaniards; petted them, lied to them—officially proclaiming that our land and naval forces came to give them their freedom and displace the bad Spanish Government—fooled them, used them until we needed them no longer; then derided the sucked orange and threw it away. We kept the positions which we had beguiled them of; by and by, we moved a force forward and overlapped patriot ground—a clever thought, for we needed trouble, and this would produce it. A Filipino soldier, crossing the ground, where no one had a right to forbid him, was shot by our sentry. The badgered patriots resented this with arms, without waiting to know whether Aguinaldo, who was absent, would approve or not. Aguinaldo did not approve; but that availed nothing. What we wanted, in the interest of Progress and Civilization, was the Archipelago, unencumbered by patriots struggling for independence; and War was what we needed. We clinched our opportunity. It is Mr. Chamberlain’s case over again—at least in its motive and intention; and we played the game as adroitly as he played it himself.

Source
The Filipino Americans (From 1763 to the Present): Their History, Culture, & Traditions.
Veltisezar B. Bautista