After the siege of Atlanta was won the victor General William Tecumseh Sherman turned his troops  towards the Sea and cut a swathe  through the state of Georgia 60 miles wide in that swathe the plan was split the confederacy in two and  to destroy anything the Confederate states could use to continue the war. 

Hence they concentrated largely on destroying the railroads. This was done by tearing up the rails heating them to forge hot heat on fires built from the sleepers and bending the rails around the trunks of trees growing in the vicinity. These rails bent double were known as 'Shermans Hairpins'

As they continued through Georgia, Sherman's troops went on a rampage destroying many beautiful houses, burning crops etc  in an attempt to deny the confederacy's will to continue the war. It was largely an exersize conducted against a civilian population and as such was a war of attrition. Sherman is credited with being one of the forfathers of modern warfare tactics, an accolade of dubious worth . 

They tore up the tracks
From Atlanta to Savannah
Piled high the fires
Along Georgia Hills
Forge hot the Rail lines
This war they'll not loose
Making 'Shermans Hairpins' again
Destroy all the contraband
In this war of attrition
Make sure that Dixie wont win