How long did it take to unblock Shanghai?

Shanghai (Shanghai and Shenzhen for short) is the national central city and megacity of China [1], the core city of Shanghai, Hangzhou and Ningbo, the international economic, financial, trade, shipping and scientific and technological innovation center [2][3], and the first batch of coastal open cities. Located at the mouth of the Yangtze River, Shanghai is the leading city in the Yangtze River Economic Belt, facing Kyushu Island across the sea, Hangzhou Bay in the south and Jiangsu and Zhejiang provinces in the northwest. [4]

In the Jin Dynasty, because fishermen created a fishing tool "Hu", the place where the river flowed into the sea was called "Hu", so the lower reaches of Songjiang were called "Hu", and later it was changed to "Hu", so Shanghai was called "Shanghai" for short? . In the third year of Xianchun in the Southern Song Dynasty (AD 1267), he set up a town in Shanghai Puxi Bank, named "Shanghai Town". In the 29th year of Yuan Dynasty (A.D. 1292), the central government designated Shanghai Town from Huating County and approved the establishment of Shanghai County, marking the beginning of Shanghai city.

Shanghai belonged to the State of Wu in the Spring and Autumn Period [8]. During the Warring States Period, it belonged to Yue State and Chu State successively, and was once the fief of Shen Jun and Huang Xie of Chu State, so it was nicknamed "Shen". In the Jin Dynasty, fishermen created fishing tools.