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In 1910, Hong moved to Gando, China. After the March First Movement in Korea, Hong became a Commander-in-Chief in the . In August 1919, Hong crossed the Tumen River with 200 soldiers. Once across the river and in Korea, Hong successfully attacked the Japanese troops in Hyesanjin and Kapsan. Hong and his soldiers would cross the Tumen River twice more, each time carrying out successful attacks against the occupying Japanese forces.