The text of this essay can be found on-line at http://www.logosjournal.com/issue_4.3/twain.htm but my reading was done from the version published in The Oxford Mark Twain, included in the Following the Equator volume. This particular book has a subtitle, "and Anti-Imperialist Essays" of which this is perhaps his best known example. My included image is from the Princeton University Press.

A person sitting in darkness is anyone that needs convincing that "Civilization" is a good thing. Old ways need to be discarded and replaced with those offered by the Blessings-of-Civilization Trust. Such people are become scarce. Too much light has been shed on actual costs and benefits fo adapting "Civilization". Mark Twain was initially for American intervention in foreign lands and was supportive of liberating Cuba from Spain. He had thought the same plan was in store for the Philippines when Dewey was sent to oust the Spanish from The Archipelago. He became disenchanted when American decided to stay and liberate the place from the Filipinos as well.

The essay is written as if from a marketing analyst for the Blessings-of-Civilization Trust. The analyst is critical of several world leaders for doing a bad job of promoting civilization by exposing the differences between Civilization for home consumption and Civilization meant for export. Criticisms are aimed at Mr. McKinley, Mr. Chamberlain, the Kaiser, the Czar and the French. A full half of the essay is a scathing indictment of American policy.