The island of Hawaii was originally a kingdom and discovered by Captain James Cook in the mid 1700s. American missionaries arrived shortly after around 1800. After the Civil War, American businessmen arrived to harvest the tremendous natural resources. The most profitable of all were pineapples and sugar. The monarchy of Hawaii rented the land to people like James Dole (of Dole pineapples).
In the late 1800s, the monarchy began to retake the land rented to landowners. This, of course, threatened Mr. Dole's, and others, business and profit. Dole, and other landowners formed the "Committee of Public Safety" and asked President McKinley to intervene.
President McKinley sent American Marines to Hawaii to negotiate with the Hawaiians. The Committee drew up a document that gave the Kingdom of Hawaii to the United States as a territory and the Hawaiian Queen, Queen Liliuokalani, refused to sign the agreement. The Marines then forced the Queen to sign the treaty at gunpoint and hence the name; The Bayonet Constitution. In 1887, Hawaii became the first real territory beyond the natural borders of the United States. In a sense, Hawaii was taken from the Hawaiian people illegally; a fact that is well known among native Hawaiian citizens.