Want to know more about the history of US aspirations towards Greenland? Type ‘Greenland’ into the search engine for the Foreign Relations of the United States (FRUS) website and you should see 434 results. When President Trump first broached the idea of buying Greenland from Denmark, in 2019, NPR ran a story, ‘FACT CHECK: Did Harry Truman Really Try To Buy Greenland Back In The Day?’, which relied on a 1991 Associated Press (AP) article based on declassified documents made recently available at the US National Archives (NARA) in College Park, Maryland. In 2025, anyone in the world using their smartphone or sitting at their desk can investigate this history. The full story is more interesting than you might expect.

The 1991 AP article cites an April 1946 State Department memo saying that ‘practically every member [of the Joint Chiefs of Staff]… said that our real objective as regards to Greenland should be to acquire it by purchase from Denmark’. It goes on to describe an internal proposal to offer $100 million (in gold) and a 14 December 1946 meeting in which Secretary of State James Byrnes brought up the matter with Danish Foreign Minister Gustav Rasmussen. ‘Our needs…  seemed to come as a shock to Rasmussen’, Byrnes wrote of this meeting, ‘but he did not reject my suggestions flatly and said that he would study a memorandum which I gave him.’

‘Ultimately, the US and Danish governments agreed on other ways to incorporate Greenland into America’s defenses,’ the 2019 NPR article concludes – namely the 27 April agreement, ‘Defense of Greenland’, under which the United States and Denmark – by that point formal allies in the 1949 North Atlantic Treaty Organization – would provide for mutual defence of the island. Articles appearing in January 2025 — such as Walter Pincus’ ‘Trump, Greenland, and a History of Intrigue’ – have spelled out some of the reasons (rare earth minerals, for example) that President Trump has taken such an interest in Greenland. However, they skip over the period between December 1946 and 1951, believing perhaps that the Danes rejected the US offer, the Americans gave up, and both sides sat down at the negotiating table. Some articles mention Secretary of State William Seward’s 1867 statement that the purchase of Greenland was ‘worthy of serious consideration’, but jump from that moment to 1946.

A simple FRUS search reveals at least two episodes between 1867 and 1951 when US policymakers considered purchasing Greenland before settling for less: between 1910 and 1916 and in 1946-47. Even if you disagree with my characterisation of these episodes, consider the ‘Greenland’ search as one example of how to use FRUS to dig into an historical topic that pops up in the news. ‘Panama’, for instance, produces 7,198 hits. The research possibilities are vast.

‘I take the liberty of making to you a confidential communication on the present state of Danish politics and finances, principally as concerning the future of the West India Islands,’ US Envoy to Denmark Maurice Francis Eagan wrote to Secretary of State Philander Knox  on 9 August 1909. ‘I do not presume for a moment to forestall in any way the intentions of the United States Government concerning these islands, but as I think the opportunity of acquiring them may some day arise, I feel it my duty, unless I am otherwise directed by you, to pave the way gently as far as possible toward that acquirement.’ Given Danish financial difficulties at that time, not only the ‘West India Islands’ (also known as the Danish West Indies or Danish Antilles; what are today the US Virgin Islands) but also Iceland and Greenland appeared to be on the table.

‘The Radicals and the Socialists would be glad to get rid of the islands which still continue to be a source of great expense,’ Eagan wrote the following year (15 July 1910). Conservatives hoped that the islands could be leveraged to obtain the restoration of Schleswig, which the Danes had lost to Germany in 1864. According to Eagan’s sources, King Frederik VIII was happy to be rid of the Danish Antilles. Yet ‘H. M. the Queen is devoted to the welfare of the colored people in the islands; she, I think, fears for their safety, if they should come under the jurisdiction of the United States.’ Greenland seemed an easier reach. ‘Denmark would cheerfully give up Greenland and even Iceland, which alternately threatens “to go it alone” or to join itself to Norway, for a part of Schleswig.’

On 20 September 1910, Eagan took things up a notch. After huddling with ‘persons of importance here’, he wrote to Washington with an ambitious proposal. In the Far East, a Russian-Japanese-Chinese combination stood poised to evict Germany from its concessions in Jiaozhou Bay (Tsingtao). ‘It seems that the interests of America and Germany are the same in eastern Asia, where neither of them wish to encroach on the territory of the natives, but where both of them wish to keep the “open door” and the “fair faced policy” in force,’ he wrote. Teaming up, ‘they would represent a force great and powerful enough to secure quiet and peaceful developments of affairs in east Asia’. And Washington had something to offer Berlin.

Eagan stated his plan: (1) ‘That Denmark should surrender to the United States of America all her enormous possessions in Greenland, estimated to be more than 800,000 English square miles in area’; (2) ‘The United States of America should in return give over to Denmark the southern group of the Philippines, consisting of the Islands of Mindanao, Palauan and the small islands south of these’; (3) ‘Denmark should then surrender to Germany all her rights to the southern group of the Philippines as she received them from America’; and (4) ‘Germany should then, in return for the southern group of the Philippines, give back to Denmark that part of the province of Schleswig which lies north of a line along the middle of “Slien”, along Dannevirke to “Trenen”, following that river to where it joins “Eideren” and then following that river to the point where it flows into the North Sea.’ Ultimately, ‘Denmark would, in exchange for a part of Schleswig, only 2,400 English square miles in area, give to America territory in Greenland as large as about one fourth of the total area of the United States of America, or a territory as large as the whole of Mexico, or about two and a half times the size of Alaska’.

FRUS does not yield a response to this proposal. Yet Eagan kept at it. ‘Greenland and Iceland do not count with the Danes as part of Denmark,’ he insisted on 21 July 1911. ‘The first, which is a monopoly, they regard as practically waste territory, and the second as the home of a very turbulent population, which would secede from Denmark tomorrow, if it could. As I have already indicated to the Department, there is another group, not undistinguished which still clings to the hope that the Danish Antilles may be made the basis of a bargain, Greenland, as a means of barter, failing, for the restoration of Schleswig to Denmark.’

One problem for Eagan was that Germany and the United States did not, in the end, team up. Still, the outbreak of the First World War on 28 July 1914, did not dampen Eagan’s enthusiasm for deal making. In light of the threat that German U-Boats posed to neutral US shipping, the opening of the Panama Canal – on 15 August 1914 – made US control of the Danish Antilles a strategic priority.

‘You will observe that the question of Greenland is involved’, wrote Secretary of State Robert Lansing to President Wilson on 4 December 1915. ‘I do not think it is of material importance, but propose to ask to what extent possession is intended, because much of the Island is still unexplored.’ Here I do not entirely understand what Lansing means – yet Wilson’s reply of 5 December, in which he asked Lansing to ask the Danes ‘just what is meant by the occupation of Greenland’, I suspect means Copenhagen proposed reserving the right to ‘possess’ or ‘occupy’ theretofore unknown portions of the island. In the deal that resulted from subsequent negotiations – the US purchase of the Danish Antilles for $25 million on 4 August 1916, a side declaration stated ‘that the Government of the United States of America will not object to the Danish Government extending their political and economic interests to the whole of Greenland’.

How seriously did US policymakers in Washington take Envoy Eagan’s proposals? Based on FRUS – which did not (but sometimes does) include excerpts from diaries and memoirs – I cannot say. Probably not terribly seriously. It is certainly the case that the Danish Antilles became far more important to Washington. The language about Greenland in the side declaration to the 1916 agreement suggests that the Wilson administration offered a salve to wounded Danish pride. After all, on 15 November 1915, Danish Foreign Minister Erik Scavenius – under instructions from Copenhagen – had sheepishly asked Lansing ‘Whether he thought in case the Danish Government did not agree to a sale of the Islands the United States would feel it necessary to take possession of them.’ No diplomat wants to ask such a question.

US policymakers thought more actively and seriously about acquiring Greenland during the period 1946-47. Strategic bombing during the war – and, afterward, the real prospect of war with the Soviet Union – forced US planners to take this idea seriously. On 9 April 1941, the United States had signed an agreement with Danish Ambassador Henrik Kauffmann that allowed US occupation of Greenland. Yet the Danish government – which had been occupied by Nazi Germany 12 months earlier – swiftly denounced the agreement and recalled Kauffmann, who stayed in Washington for the rest of the war. Later, in December 1946, Secretary of State Byrnes approached the Danish Foreign Minister, Rasmussen, with his proposal to purchase Greenland. Kauffmann remained Ambassador to the United States under Denmark’s postwar government, even though the 1941 agreement was unpopular (though not as unpopular as it had been with the Nazis).

On 2 January 1947, Secretary Byrnes wrote to the legation in Copenhagen, led by Josiah Marvel, requesting that he call on Rasmussen to follow up on the December 1946 conversation, which the FRUS editor summarised non-verbatim in a footnote. Byrnes wrote to Marvel:

You may say you know your Government attaches highest importance to a satisfactory solution of the Greenland problem and will, of course, be interested in learning Rasmussen’s personal reaction to the possible courses of action which I outlined to him; that you are not in any sense pressing him to reply now but when he has had time to consider the matter further you will be glad to transmit his thoughts to me.

‘Although I requested his personal views’, Marvel responded on 7 January, after seeing Rasmussen the previous evening, ‘he volunteered no reaction to the possible courses of action outlined by you except to state that this thinking came as a shock to him and that he believes US greatly over-emphasizes strategic location of Greenland.’ Still, Rasmussen ‘was quite relieved’ to hear that no immediate action should be taken – especially because word of it could disrupt quiet Soviet-Norwegian negotiations over the boundaries of Spitzbergen (Svalbard), the archipelago in the Arctic Ocean. Closer to home, communist members of the Parliamentary Committee in the Danish government would have a propaganda field day by claiming that the United States was setting up bases presumably from which someday to wage war with the Soviet Union.

Indeed, US military planners regarded the Arctic as critically important at the dawn of the Cold War. ‘The security interest of the United States in the region, particularly in the zone Alaska-Canada-Greenland-Iceland, has been indicated in a concrete manner by military measures taken by the United States during the war on its own territory in Alaska and in conjunction with the local governments in Canada, Greenland and Iceland,’ read a memo from 27 January 1947. ‘This interest has been stated by the Joint Chiefs of Staff to be a long-range interest, and efforts are, therefore, being made to secure the necessary cooperation and rights from the governments controlling those areas (Canada, Denmark, Iceland).’

Still, US policymakers appeared to grasp the difficult position in which their Danish counterparts found themselves – especially following the harsh winter of 1946 and economic deterioration throughout Europe. ‘[Prime Minister Knud Kristensen’s] attitude continues consistently pro-American; but he is faced with lack of majority votes in Parliament; strict adherence to party discipline by each party; and fact each party’s action is motivated by local political advantage,’ Ambassador Marvel reported on 23 May 1947. ‘It is not acquiescence to Communist attitude but realistic approach to his own political survival which he will not risk by voting against such resolution when by later directing non action thereon he can effectively show his true feelings.’ The following day he wrote that Prime Minister Kristensen ‘believes Germany has good chance of becoming Communistic and without adoption his plan, Communism, with greatly increased population, would beat Denmark’s door and infiltration easily accomplished’. Kristensen also ‘strongly reiterated his hatred of Communism and his belief in western democracies’. ‘While stating this was view of govt and majority of people, he pointed out he must maintain for Denmark neutral outward appearance.’ (This was two years before the 4 April 1949 North Atlantic Treaty.)

Maintaining Danish neutrality – especially on Greenland – mattered because of the complex problem of German refugees who had fled to Denmark as the Red Army headed westward to Berlin. Danes were not enthusiastic for them to stay, but the refugees did not wish to leave. Nor did the Americans wish to resettle them quickly into its zones of occupation in the western part of Germany. Stalin was happy to exploit this situation in any way possible.

Sworn in as secretary of state (replacing Byrnes) on 21 January 1947, George Marshall appreciated both the military and political concerns when it came to Greenland. ‘I told Ambassador Kauffmann that I had had a good bit of personal experience with the Greenland question and that I could tell him that it is of fundamental importance to the security of the US to keep an enemy state out of Greenland.’ He recounted a meeting with the Danish Ambassador on 17 June: ‘I told him that we had faced the problem of driving the Germans out of Greenland in World War Two, adding that the weather information which they obtained in Greenland had been a material factor in German offensive operations in Europe against us and our Allies.’ Marshall also ‘said that relations between the US and Denmark are of course excellent and that our apprehension would be met if we could be sure that our friend, Denmark, was in a position adequately to defend Greenland’. To the secretary’s view that Denmark was ‘not in such a position’, the ambassador ‘readily assented’.

Marshall stressed his intention to ‘make it as easy as possible for the Danish Government to answer critics, some of whom would of course denounce whatever action was taken for their own selfish reasons’, and said that the US ‘would gladly explore any ideas that might contribute to a satisfactory solution’. He cited as a potential idea one he had recently proposed for the US Naval Base on Manus Island, whereby the US would pay Australia an annual sum ‘to conduct maneuvers in peacetime and of course unlimited use in wartime’. The secretary admitted that he did not know whether ‘this would be suitable at all in the Greenland situation’.

Two days after Marshall met with Kauffmann, Ambassador Marvel wrote from Copenhagen (on 19 June) that it was simply not possible to disaggregate negotiations about Greenland from the matter of the German refugees in Denmark. Stalin would retaliate by refusing to resettle his share of the refugees – even though he would publicly accuse the US and its allies of not resettling 50 per cent of the German settlers as a justification.

Marvel wrote again on 26 June, having dined privately in Copenhagen with Ambassador Kauffmann, ‘who emphasized that there was no possibility of a sale [of Greenland]’, yet expressed optimism that some deal could be struck on US basing rights later that autumn. It was very important, however, for the US to get out in front on the resettling of German refugees to pre-empt Stalin. All Danes but the Communists had fond regards for the Americans, Prime Minister Kristensen apparently told Marvel on 25 July. On 19 September, Marvel spoke with Hans Hedtoft, the leader of the Danish Social Democrats, who was expected to form a new government after elections that autumn, and who apparently told Marvel that he could produce a basing agreement on Greenland so long as American forces remained in Germany.

Keep going with the FRUS search and you will find that US and Danish leaders figured out how to commence negotiations that ultimately led to the 1951 agreement. What emerges during the period 1946-47, however, is a story about how US policymakers considered the purchase of Greenland – something they regarded as the simplest option – while also weighing the potential that such action would reify Soviet charges about US aggressive intent. However absurd those charges may be, they might still usher in communist regimes through democratic elections.

In his 5 June 1947, speech at Harvard, Secretary Marshall laid out what became known as the ‘Marshall Plan’ to empower European economic recovery. Yet President Harry Truman would not sign that into law until 3 April 1948; in the meantime, Marshall faced a considerable challenge to convince Congress to dole out $13.3 billion ($175 billion in 2025 dollars). So long as it could lead to the US fulfilling its strategic requirements, patient negotiations on Greenland proved to be the way to go then. That neither means it should (or will) be the case in 2025.

The views expressed here do not necessarily reflect those of the US Government or the US Department of State.