1775, "what is stated," from state (v.) + -ment. From 1789 as "action of stating;" 1885 in the commercial sense "document displaying debits and credits."
also state-room, 1703, room reserved for ceremonial occasions; earlier (1650s) "a captain's cabin;" from room (n.) + state (n.1) in a sense also preserved in stately.
c. 1600, in reference to church-state matters; 1880 as "the art of government;" by 1912 as the modern political opposite of individualism; from state (n.) + -ism.