text: In 1453, the ban on using coins for trade was lifted. From the mid-1450s, illegal private coins from Jiangnan began to dominate the markets in Beijing, replacing the old Yongle coins. Although there were some proposals to address this problem by resuming state production, they were disregarded, resulting in the spread of illegal mints through unofficial networks.
  After the severe floods and changes in its course in 1448, the government took urgent action to regulate the Yellow River. As a result, the river began to flow into the sea both north and south of the Shandong Peninsula. However, these changes in the river's flow caused problems with the water supply for the Grand Canal. Despite attempts to fix the issue and repairs carried out from 1449 to 1452, they were ultimately unsuccessful. In 1453, Xu Youzhen (), who had fallen out of favor during the crisis of 1449 when he suggested relocating the capital from Beijing to Nanjing, presented a plan to rebuild the levees and canals. With a workforce of 58,000, he completed complex repairs to the dams and excavated hundreds of kilometers of canals within two years. His work successfully withstood the great flood of 1456 and remained in use for decades.