The United States annexed the islands of Fiji in 1844, Samoa in 1856, Marshall Islands in 1881, and the Philippines in 1898. These islands were annexed specifically due to their strategic locations and economic interests in Asia, for instance, trade of tea, porcelain, and silk. They were also annexed for replenishment of supplies and goods acquisition to trade with the Chinese merchants.
The annexation of Hawaii enabled the United States to gain possession mad control of all ports, buildings, harbors, military equipment, and public property that once belonged to the Hawaiian government.
The United States also established formal diplomatic ties in these islands in order to protect the interests of it's citizens.
Finally, the United States set up military administration to govern these islands and promote their political, economic, and social development.