The Historical Background of Establishing Customs and Sanitation Facilities in Xu Da

In the second year of Hongwu in the Ming Dynasty, the general Xu Da was ordered to guard the north, "all the passes over 2,000 miles west of Yongping were guarded". Later, the Ming government began to adopt two policies in this area, namely, reclaiming land and keeping the border by immigrants. Although the implementation of these two policies has greatly strengthened the border defense, the Ming army's elusive raid on Mongolian cavalry is still hard to prevent. In the winter of the sixth year of Hongwu, cavalry led by Ai You and Li Dala invaded Funing County and looted the whole city. Then it swept eastward and looted Qian Min Town (now Shanhaiguan area) near Funing County and Ruizhou (now Qianwei Town, Suizhong County, Liaoning Province) to which Qian Min Town belongs. Funing County, ravaged by the Yuan Army, was devastated, and Ruizhou was razed to the ground, and Qian Min Town was almost deserted. In the winter of the 13th year of Hongwu, the Northern Yuan cavalry raided Qian Min Town again and met the well-trained Xu Da Tiejun. Xu Da captured those people who lost their money without spending money, and Nair ran away without spending money. This great victory attracted the attention of General Xu Da to the strategic position of Qian Min Town. He begged Zhu Yuanzhang, the founder of Ming Dynasty, to set up a guard in Qian Min Town, and Zhu Yuanzhang also realized the necessity of "building a high wall" here.