Estate of the Union


The United States started life as colonies strung along the Atlantic seaboard of the North American continent and barely extending 50 miles inland. By the time of the Declaration of Independence, these original 13 colonies occupied an area roughly one-tenth of today’s country. Over the next 200 years, the United States great to fill the massive continent to the Pacific coast. Who were the Presidents who oversaw the country’s greatest expansions?

In over two hundred years of nationhood, the United States of America has more than fulfilled its ‘manifest destiny’ to stretch from ‘sea to shining sea’. From the original 13 colonies clustered on the northeastern seaboard, the country has stretched southwards and, most importantly, westwards. ‘Go west, young man go West and grow up with the country’ urged Horace Greeley. And they did, in their millions, pushing beyond the Appalchians and over the Rockies until America finally stretched from coast to coast.

Expansion of the United States using the faces of the four main contributors to expansion (own work)

With the addition of two non-contiguous states (Hawaii and Alaska) and a series of island territories, the United States today covers 3,794,101 square miles – just shy of 2.5 billion acres and the third largest country in the world (after Russia and Canada), although this third place is disputed by some who suggest China is the world’s third largest country. Still, to put this in perspective, this is over 40 times larger than the United Kingdom and over twice as big as the 27 member states of the European Union.

The United States did not expand with a single massive land grab or in a gradual, steady accumulation of territory. Instead, the country bought and fought its way to its current shape, its additional land being acquired in a series of landmark steps. This piece looks at these acquisitions in order of their size, from the largest to the smallest.

1. James Polk and the Mexican Cession, Texas Annexation and the Oregon Treaty

When I set out to write this piece, I was pretty sure that President Jefferson would be a slam dunk for the top spot. He was the President at the time of the Louisiana Purchase, the single biggest territorial acquisition by the United States (see two below). But with three substantial additions to the country during James Polk’s presidency, it is America’s 11th president who presided over the USA’s greatest territorial expansion.

In total, Polk’s administration oversaw the absorption of 1,188,749 square miles, almost one-third of the present day United States. This territory, the western third of the union, covers an area just under that of modern day India. It came to the United States following negotiations with Britain and war with Mexico.

In 1836, Texas gained its independence from Mexico. Less than 10 years later, its people voted to join the Union as the 28th state. Although much of this had been decided under the administration of Polk’s predecessor, John Taylor, it was Polk who signed the formal documents integrating Texas into the United States on 29 December 1845. With Texas came at least 383,590 square miles in addition to claims over a vast expanse further west.

James Knox Polk by GPA Healy, 1858 George Peter Alexander Healy [Public domain], via Wikimedia Commons

Tensions with Mexico would escalate into the Mexican-American War of 1846-48. Spectacular successes by the US Army would lead to the comprehensive defeat of the Mexican Army and the capture of Mexico City. Mexico sued for peace and unsurprisingly paid a heavy territorial price for its military failings. Under the Treaty of Guadalupe Hidalgo, 522,902 square miles was ceded to the United States. The current states of California, Nevada, Utah and Arizona and the parts of Colorado and New Mexico not acquired by the Texas Annexation were all  hewn out of the Mexican Cessation.

Finally, President Polk signed the Oregon Treaty which brought an end to competing British and American claims to Oregon County in the continent’s north-west. A compromise drew the boundary along the 49th parallel, dividing Oregon County between what would become the American states of Oregon, Washington, Idaho and parts of Montana and Wyoming to the south of the line and Canada’s British Columbia to the north.

In all, part of the territory of at least 12 states of the Union were brought into the Union under Polk’s administration.

2. Thomas Jefferson and the Louisiana Purchase

Under President Jefferson, a single territorial expansion would change the nature of the United States and form the basis for its expansion over the next century. The Louisiana Purchase of 1802 saw at least 817,885 square miles added to the country. A timely overture to an overstretched and indebted Emperor Napoleon saw France accept $15 million (or approximately $284 million in 2012 dollars) in payments and debt cancellations.

Louisiana Purchase Commemorative 1904 Issue By US Post Office (US Post Office) [Public domain], via Wikimedia Commons

This was one of the greatest bargains in American history, with the land costing less than 4 cents per acre in 1802 (less than 60 cents per acre in modern prices). What did America get for its $15 million? Territory that would make up all of the present-day states of Arkansas, Missouri, Iowa, Oklahoma, Kansas, and Nebraska, most of North and South Dakota and parts of Minnesota, New Mexico, Texas, Montana, Wyoming, Colorado and, of course, Louisiana west of the Mississippi River, including the city of New Orleans.

Perhaps most importantly, it gave the USA control of the Mississippi River system and made its ‘manifest destiny’ plausible if not inevitable.

3. Andrew Johnson and the Alaska Purchase (‘Seward’s Folly’)

So, was the Louisiana Purchase the greatest bargain in America’s history? Possibly, but it faces stiff competition from the purchase of Alaska in 1867. It didn’t seem like such a great bargain at the time – various newspaper editors complained that ‘the country would be not worth taking as a gift’, that it was ‘a frozen wilderness’ and that it ‘contained nothing of value but furbearing animals, and these had been hunted until they were nearly extinct’.

It seems strange today to imagine Alaska as the heart of Russia’s American empire. The Tsars had extended their vast realm so far eastwards that they had reached the Baring Straits and crossed it to claim the territory of modern day Alaska as Russian America under the control of the Russian-American Company. But Russia feared it had overextended herself and that the territory was ripe for conquest by the neighbouring British in Canada.

William Seward, Secretary of State,By Mathew Brady [Public domain], via Wikimedia Commons

Instead of being ignominiously turfed out of America, the Russians decided to sell Alaska to the Americans. The price set for this frigid slice of Arctic territory was $7.2 million, or about 2 cents per acre for the 586,412 square miles (an area more than twice the size of Texas and four times the size of California). The negotiations were conducted by Secretary of State William Seward and to many sceptics the purchase was known as Seward’s Folly.

History would prove Seward’s astute decision in ways that even he couldn’t have imagined. Alaska is rich in gold, copper and, of course, oil. It also occupies a strategically important position in relation to both Russia and the Pacific which would prove invaluable during the Second World War, the Cold War and in today’s increasingly Pacific-orientated world.

5. James Monroe and the Florida Cession

An ailing Spanish Empire would provide plenty of opportunities for American territorial expansion. The first of these was the Florida (or Spanish) Cession. The 67,723 square miles brought by the Adams–Onís Treaty and bought from Spain covered land comprising modern day Florida and Alabama and  parts of Mississippi, and Louisiana.

6. Franklin Pierce and the Gadsden Purchase

In 1853, the President formally signed the treaty that would bring an additional 29,670 square miles in the south of Arizona and New Mexico into the Union. The agreement had been thought strategically important to allow the constructions of a southerly trans-continental railroad and to settle border disputes between America and Mexico unresolved by the earlier Treaty of Guadalupe Hidalgo (see point one above).

Map of the Gadsden Purchase and the Southern Pacific Railway

The purchase was significantly more expensive than either the Louisiana or Alaska purchases or the amounts given to Mexico under the Treaty of Guadalupe Hidalgo. The Gadsen Purchase cost the US $10 million (or $258,666,667 in today’s prices), over 50 cents an acre (or approximately $13.5 an acre in today’s prices).

7. William McKinley and the accession of Hawaii, Guam and Puerto Rico

The dismemberment of the Spanish Empire would continue under William McKinley, with the absorption of Guam and Puerto Rico as US territories. His presidency also oversaw the accession of the previously independent kingdom of Hawaii. In total, an additional 14,655 square miles of territory were added to United States control.