- US annexes Canada in ARW or War of 1812
- Successes in Canada mean that by the Manifest Destiny rhetoric rolls around, virtually all mainstream political parties are receptive to it
- Texas settlement, Revolution, and Republic more or less as OTL
- Mex-Am war results in total annexation of Mexico due to North-South balancing act politics and general enthusiasm for Manifest Destiny expansionism
(On a side note, I think Franco-Prussian War will go as OTL-- French still get the warning signs from the Austro-Prussian War, (Prussian army is strong) but doesn't get any of the warning signs about the weakness of its own forces gleaned from the adventures in Mexico.)
- Civil war eventually breaks out, won by Union
- Dominican Republic annexed some time in 1870s similar to OTL's proposal, Liberia likely annexed along similar lines.
- Spanish-American war goes more or less as OTL, but Cuba is annexed outright within a decade of the Treaty of Paris.
- Banana Wars and other assorted C. American occupations lead to annexation of virtually all of Central America and Haiti by the end of WW1
- US purchases St. Thomas and Virgin Islands from Denmark, as OTL, but is also able to buy Greenland by convincing Denmark that it needs extra money to build up military forces in event of either CP or Entente invasion, and that Greenland could be used for the basing of German U-boats, or for the basing of RN vessels intended to interdict US-European trade in the event that US enters WW1 on CP side. At this point, US public opinion could go either way-- Germans have invaded Belgium as OTL and British maintain a near monopoly on propaganda, but Germany never reinstates USW and public opinion instead shifts to how British blockade of Germany is starving thousands of innocent German civilians- and hurting the US economy.
- Eventually, the British do something stupid. This coupled with a desire to seize Entente territories in both the Pacific and the Carribean lead to US declaring war on the Entente.
- Main purpose of US forces is to divert Entente attention away from Europe- US seizes Belize, British Guayana, French Guayana, St. Pierre and Miquelon, Bermuda, and all Entente territories in the Carribean. US forces in Liberia invade Entente possessions in Africa. US forces in Pacific reclaim occupied German territories (minus Kiautschou Bay) and seize Entente possessions in the Pacific.
- Imperial Russian forces seize Svalbard (which, at the time, I believe, was more or less owned by Norway (which remains neutral) but would not be officially so until the 1920 Paris Peace Conference) as a stepping stone to seizing US-held Greenland.
- US forces are eventually able to take Svalbard, and one of the last actions undertaken before Russia's withdrawal is a US operation to take Franz Josef land.
- the CPs + US win WW1. In the peace settlement, the US gains all its Carribean/American conquests, granting it control over Belize, SP&M, French Guayana, Bermuda, and all Entente Carribean territories.
In Africa, Sierra Leone is annexed to Liberia, a US territory.
In the Arctic, a US-Norwegian condominium is established over Svalbard, while the US gains full control over Franz Josef Land.
In the Pacific, the US gains all Entente Pacific islands, including the Japanese Bonin and Marcus Is., the French Clipperton Is., and all those other central Pacific islands that I can't be bothered to name. The peace settlement returns Germany's Pacific possessions to Germany, (minus Tsingtao, which remains in the hands of Japan) and adds British New Guinea to German New Guinea, but Germany decides to sell those possessions to the United States after the conclusion of negotiations.
- Some time after WW1, the US needs to sell its New Guinean territories to the Netherlands in exchange for the Dutch Carribean and Dutch Guayana. Some money may also need to be ceded to the Netherlands in order to lubricate the deal.
- The US should also try and cultivate good relations with Albania. Assuming such attempts are successful, the US may be able to annex Albania via referendum in the late 20th century.