By 1864 the top Union generals Ulysses S. Grant and William T. Sherman realized the weakest point of the Confederate armies was the decrepitude of the southern infrastructure, so they escalated efforts to wear it down. Cavalry raids were the favorite device, with instructions to ruin railroads and bridges. Sherman's insight was deeper. He focused on the trust the rebels had in their Confederacy as a living nation, and he set out to destroy that trust; he predicted his raid would "demonstrate the vulnerability of the South, and make its inhabitants feel that war and individual ruin are synonymous terms." Sherman's "March to the Sea" from Atlanta to Savannah in the fall of 1864 burned and ruined every part of the industrial, commercial, transportation and agricultural infrastructure it touched, but the actual damage was confined to a swath of territory totaling about 15% of Georgia. Sherman struck at Georgia in October, just after the harvest, when the food supplies for the next year had been gathered and were exposed to destruction. In early 1865 Sherman's army moved north through the Carolinas in a campaign even more devastating than the march through Georgia. More telling than the twisted rails, smoldering main streets, dead cattle, burning barns and ransacked houses was the bitter realization among civilians and soldiers throughout the remaining Confederacy that if they persisted, sooner or later their homes and communities would receive the same treatment.