Answer:
The Great Migration
Explanation:
The Great Migration was the relocation of more than 6 million African Americans from the rural South to the cities of the North, Midwest and West from about 1916 to 1970. Driven from their homes by unsatisfactory economic opportunities and harsh segregationist laws, many blacks headed north, where they took advantage of the need for industrial workers that arose during the First World War. During the Great Migration, African Americans began to build a new place for themselves in public life, actively confronting racial prejudice as well as economic, political and social challenges to create a black urban culture that would exert enormous influence in the decades to come.
The nickname "China's Sorrow" memorializes the millions that have been killed during the Huang He River's many diversions and floods. Most notably, in June 1938, the Nationalist Chinese Army used the river to block the Japanese army, killing an estimated 800,000 Chinese citizens and very few Japanese soldiers.