About the Book

In his first term, President Donald Trump privately raised an idea so far outside the Washington mainstream that it shocked his inner circle. His advisers couldn’t be sure at first whether he was joking or serious. Trump wanted the United States to buy the island of Greenland. Aides were confused, then skeptical, until Trump made it clear that he was entirely serious. He grew increasingly excited at the prospect of making the largest real estate deal of his career. It would be America’s first territorial expansion in the 21st century. Adding the world’s largest island would make America the second-largest country in the world, overtaking Canada. Borders that had seemed fixed would move again. In the republic’s early years, it grew by repeatedly buying, negotiating for, and conquering territory. So why, Trump asked, couldn’t America do it again?

Trump ended his term in 2021 without any noticeable progress toward acquiring Greenland, and for a time, the episode was mostly forgotten. But it made me wonder: What other foreign lands could have been added to the United States? Why did America annex some places but not others? And what would the U.S. look like today if it had gained all of the territory it could have? 

I decided to make a post on Reddit. It would have been a map showing all of the potential annexations in America’s history. I expected it would take me about 20 minutes. I shaded today’s U.S. territory in blue, and possible land acquisitions in red. So first, I colored Greenland red. Then I added red to Canada and Mexico, since both have been targets of numerous attempted land grabs. That created a large, contiguous, colored area over North America. Then I shaded Cuba, an island in America’s sights for most of the 19th century and into the 20th. And the Philippines, on the other side of the Pacific, which the U.S. annexed but later granted its independence. I’d also need to add all of the far-flung islands that the U.S. once claimed around the world, which are now part of other countries. That would put little red dots across multiple oceans (plus some blue dots for the territories that the U.S. took and kept). The map was starting to fill up. This was a bigger project than I had expected. The more research I did, the more annexation targets I learned about: Russian Arctic islands, part of Malaysia, the Dominican Republic, and Haiti. The red was creeping across the globe. 

My text accompanying the map kept growing, too, as I added more historical details. But it all remained a draft. I couldn’t post anything because there was more information I needed to include. I kept learning more stories of potential annexations: Indonesia, Ecuador, Taiwan. The more rabbit holes I went down, the more history I unearthed: America’s possible annexations have been vast. I’ve been reading about history and geography all my life, but I was surprised at how many stories I was learning about for the first time. There was enough history here to fill a book. So I wrote one. 

Whether seeking natural resources, trade wealth, military advantage, slavery, humanitarian goals, or just the thrill of conquest, both Americans and foreigners have engaged in an almost continuous effort to expand U.S. borders for over 250 years. Manifest Destiny was a 19th-century phrase, but American expansionism predates the Declaration of Independence. Since its founding, America has successfully acquired territory that had been held by the United Kingdom (and its Canadian colonies), France, Spain, Mexico, Russia, independent Hawaii, Samoa, Denmark, and Japan, as well as numerous Native nations. That’s how the country grew from 13 colonies hugging the Atlantic coast to 50 states and 14 territories spanning the globe today. This book isn’t about the lands the nation acquired and still possesses. It’s about the might-have-beens: the annexation attempts that would have changed the size, culture, politics, and demographics of the country—dramatically or minutely—if they had succeeded. 

I learned from my research that these attempted annexations have included the territory of at least 40 of the modern countries of the world (maybe over 60, depending on what you count). That’s at least one in five countries that would be smaller today—or not exist at all—if the annexationists had succeeded. Some of the lands were sought through war, some by diplomacy, some by exploration. Some, like Trump’s interest in Greenland, were attempted purchases. Some places had populations that welcomed Uncle Sam’s embrace or even asked to join the Union. Others tenaciously fought American advances. Others had no population at all. Some territories were taken and then let go again, like fish caught and then released back into the sea. Either they steadfastly resisted annexation, or America lost interest. The histories of these unsuccessful expansions include tales of bravery, greed, altruism, hubris, racism, hucksterism, and larger-than-life characters. They are America’s history in microcosm.