The answer is Moore's Laws
If a person lived through the conquest of Kublai Khan, they would live to see massive public works programs. These include building and repairing of roads and the construction of a great canal system in China. Kublai Khan also constructed fabulous palaces.
School systems were shut down instead of integrating schools
The Battle Stalingrad was the turn point against Germany in World War II
Yes he did create change johnson did good