How did the united states build an overseas empire

to one answer USA Building an empire started with the so called Manifest destiny after the war or 1812 the USA signed that the west would be for the Indians then increased their empire? well they needed the land after failing t put Canada in their empire they stole Texas from the Mexicans they stole Hawaii from the Royal family the Purchased Alaska they forced the UK into a fire sale then took Land for Goods sorry 99 year leases Just Like the Colony if Hong Kong