In 1890, the USA was far from being a world power its foreign policy was essentially defensive, seeking to keep America out of wars and foreign entanglements. Most Americans were hostile to the ideas of imperialism. However, the events of 1890s pushed USA into rapid naval expansion, Spanish-American war and annexation of territories in the Pacific Ocean- far from the USA.
One reason why the USA expanded was due to economic reasons. Rapid increase in economy proved that the US needed to control new markets. America’s industrial economy experienced a downturn after a rapid growth in the 1870s-1880s by 4% annually .The successful war between Spain allowed the USA to expand and establish an empire as the war included the annexation of other Spanish possession in the Caribbean and pacific this lead to USA also gaining control over Puerto Rico, Guam, the Philippians and Hawaii. Taking over new colonies meant cheaper raw materials would be available and more money would be coming in; this was especially needed with growing industrialisation.
Another reason why the USA expanded was because of the militarily. Spain made peace at the Treaty of Paris in July 1898 and Cuba remained under American military rule until 1902, when it became an American. Expansion of the Navy meant better protection interests and trade abroad. Protectorate. The war of 1898 also lead to the Platt Amendment which allowed the USA to protectorate smaller colony such as Cuba this lead to the Guantanamo Bay naval base was also acquired. USA had to be a major naval power which required the achievement of colonies to supply bases around the world. Also powerful nations in History had always been strong sea powers.
Final reason why the USA expanded was because of nationalist. Some Americans felt it was the "Manifest Destiny" of the USA to dominate the Northern half (encouraging western expansion beyond