Why are there so many Hakkas in Sichuan?

Commander-in-Chief Zhu De is a Hakka in Yilong County, Nanchong City, Sichuan Province. Sichuan is a province composed of immigrants and the largest inland province in the west, with the largest number of Hakkas. Sichuan Hakka is composed of six parts: first, during the period from Kangxi to Jiaqing in Qing Dynasty, Hakka migrated to Sichuan to breed more than 2 million people; Second, during the Anti-Japanese War, Hakka people in Guangdong, Fujian, Guangxi and Jiangxi, mainly in Huizhou, moved to Sichuan to avoid persecution by the Japanese aggressors. Third, when New China was founded, the Hakkas among southern cadres settled in Sichuan. Fourthly, since 1950s, in order to support the economic construction in Sichuan, many Hakkas from other provinces went to work in Sichuan and stayed in Sichuan. Fifth, visiting college graduates are selected by the state to work in Sichuan and stay in Sichuan for a long time; Sixth, overseas Chinese returned to their motherland and settled in Sichuan. At present, the Hakkas in Sichuan are mainly distributed in Longquanyi District, chenghua district, qingbaijiang district, Xindu, jinniu district, Jinjiang District, Jintang, Guanghan, Deyang, Shuangliu, Xinjin, Wenjiang, Pixian, Dujiangyan and Shifang in western Sichuan. Jiangyou, Santai, Anxian, Yilong, Yanting, Bazhong, Tongjiang and Guang 'an in northern Sichuan; Neijiang, Longchang, Zizhong, Ziyang, Renshou, Pengshan, Fushun, Weiyuan, Luzhou and Yibin in southern Sichuan, and counties (cities, districts) such as Xichang and Huili under Liangshan Prefecture, especially the eastern suburbs of Chengdu and Longchang in Tuojiang River basin, as well as Yilong and Xichang.