It was really more of a coup engineered by a cadre of well-connected Americans, but "annexation" sounds much more pleasant.
In 1898, the repugnant corporatist William McKinley ordered Hawaii stolen from the Hawaiians in repudiation of Cleveland's earlier attempts to keep McKinley's pals from seizing control of the Islands.
Cleveland wrote in 1898: "Hawaii is ours...As I look back upon the first steps in this miserable business, I am ashamed of the whole affair."
A month later, "the same flag Cleveland had ordered hauled down was raised again in token of American sovereignty."
--From Grover Cleveland: A Study in Character by Alyn Brodsky