Building techniques improved, iron became more common, and hydraulics were used to dig riverbeds deeper. So less floods happened that destroyed farms and endangered lives.
        
             
        
        
        
"The Truman Doctrine was an American foreign policy whose stated purpose was to counter Soviet geopolitical expansion during the Cold War."
 
        
                    
             
        
        
        
Europe to Asia from 1271 to 1295