December 10 is the anniversary of the signing of The Treaty of Paris in 1898. This formally ended the Spanish-American War, which had been ongoing for 6 months.
The treaty transferred control of Guam, Puerto Rico, and The Philippines from Spain to the US. It was not possible to annex Cuba in the treaty, as the war was partially justified by seeking "Cuban Freedom". However, the US would place troops there, and the following century would see much meddling in Cuba's affairs in an effort to bring it to heel. The additions of the Spanish colonies marked the first of the US conquests outside of North America. The US regime now had a significant foothold on the Pacific, which they could use to further their ambitions.
Manifest Destiny had now expanded its scope, and more colonies were added in the next decades. Eventually Cuba and the Philippines would slip away, and the US regime would move away from direct colonial administration. They've laid claim to the entirety of the Americas. Today, the US has over 800 military bases outside of its borders stretching over the globe. They dictate terms to the world, and the list of their interventions is extremely long for those who challenge their authority.