Final answer:
The monarchy of Hawaii was overthrown by the Hawaiian League and a group of European and American businessmen with U.S. military support, resulting from the imposition of the 'Bayonet Constitution' and a coup against Queen Lili'uokalani's attempt to restore the monarchy's power.
Step-by-step explanation:
The two groups that helped overthrow the monarchy of Hawaii were the Hawaiian League, consisting largely of White American businessmen, and a group of European and American businessmen backed by the United States military. This pivotal historical moment occurred during the late 19th century when the Hawaiian League first imposed the "Bayonet Constitution" on King Kalākaua, severely reducing the monarchy's power. Later, in response to Queen Lili'uokalani's efforts to restore the monarchy's authority, a coup led by foreign businessmen and supported by the U.S. military ultimately dethroned her. The presence of U.S. Marines with Gatling guns outside the royal palace demonstrated the overwhelming force the Queen faced, which led to her surrender in hopes of preventing bloodshed and being reinstated after possible intervention from the U.S. government.
Opposition to the changes brought by Queen Lili'uokalani, who sought to restore rights to native Hawaiians and maintain Hawaiian independence, was primarily from American sugar planters and other foreign businessmen who stood to gain from annexation of the islands to the United States. This was because annexation would eliminate tariffs on their sugar exports to the U.S., significantly benefiting their businesses. These interests, together with military support, led to the overthrow of the monarchy and eventual annexation of Hawaii to the United States, with Sanford B. Dole being appointed as the president of the provisional government.