 McClellan 's experiences in the war would shape his military and political life . He learned that flanking movements ( used by Scott at Cerro Gordo ) are often better than frontal assaults , and the value of siege operations ( Veracruz ) . He witnessed Scott 's success in balancing political with military affairs , and his good relations with the civil population as he invaded , enforcing strict discipline on his soldiers to minimize damage to property . McClellan also developed a disdain for volunteer soldiers and officers , particularly politicians who cared nothing for discipline and training . 
