[Working backward from the year 2000 toward America’s beginnings.]
The economic transformation of the United States in the years between 1900 and its entrance into World War I in 1917 was not dramatic, but it held the seeds for many things.
For one thing, the country for the first time had overseas possessions. The War of 1898 and the events around it had brought several previously Spanish territories under the American flag. Cuba we probably could have annexed (who could have stopped us?) but domestic sugar interests did not want Cuban sugar within our tariff walls, and southern congressmen did not want a largely Negro and mestizo population added to the population. However we did hold onto Puerto Rico, as well as the splendid area for a naval base at Guantanamo Bay, on Cuba’s south coast. The treaty with the new republic of Panama, following the revolution/coup of 1903 that severed it from Columbia, had brought us the Canal Zone, a 10-mile-wide strip of land extending from coast to coast.
In the Pacific, America took the Philippines and the islands of Guam, Wake, Midway and American Samoa, and in 1900 acquired the Hawaiian Islands by shifty dealings.
All this worked together as part of the two-ocean navy strategy that was assumed to be needed for America to take its proper place as a world power. If you were going to have a two-ocean navy, the Panama Canal would allow you to transfer armored might from one ocean to the other as the need arose. If you were going to operate in the Pacific, you would need a series of coaling stations. Hence, starting from our west coast, Hawaii, Midway, Wake, Guam, American Samoa and the Philippines. Besides coaling stations, you would need repair facilities and safe harbors – in short, navy bases. Hence Guantanamo Bay, Cuba; Roosevelt Roads, Puerto Rico, defenses for the canal on each coast, Pearl Harbor, Hawaii, and bases on the remaining islands. It’s simple enough when you understand the logic.
Of course, an alternative course would have said, we don’t have an overseas empire, we don’t need an overseas empire, and so we don’t need to be doing all this to provide support for a two-ocean navy to defend the empire we don’t have. But anti-imperialists (there was an Anti-Imperialist League, and Mark Twain was one prominent member) didn’t get any farther then than they do now. They’re always at a disadvantage when their opponents start waving the flag. So we acquired our territories, and our bases, and new neighbors such as the Empire of Japan, which wasn’t especially happy to welcome us to the neighborhood.
In 1917, just about the time we entered the war, we bought the Virgin Islands from Denmark, as additional protection for the Atlantic approaches to the Panama Canal, and this rounded out our acquisition of overseas real estate.