Answer:
Meiji Restoration
Explanation:
United states knocked the door of Japan in 1853 when Commodore Perry arrived in Japan with large warships to conclude the treaty with Japan to open its ports for trade. Japanese knew that they have little choice as they could not stand a chance against westerners. This evoked a feeling to strengthen Japan and by 1868 it came under an imperial rule of emperor Meiji. And the modernization of Japan started with this event called Meiji restoration.