In August 1863, Quantrill, Bloody Bill Anderson and about 450 other Confederate "bushwhackers" burned Lawrence, Kansas and murdered circa 180 men & boys.
That puts Lawrence on the map along with Chambersburg, PA, which suffered three Confederate raids (1862, 1863 & 1864), eventually burning most of the city.
These examples of Confederate behavior in Union states all preceded General Sherman's famous march to the sea in December 1864.
There's no direct evidence that Sherman's army murdered any Confederate civilians.
Here is Quantrill's headstone at Higginsville, MO.
Note the words CPT and CSA:
During the Gettysburg campaign, Confederate troops restrained themselves from destroying non-government property. By the Rebels' next raid into the North, however, the policy had changed.
On July 30, 1864, Brigadier General John McCausland and 2,800 Confederate cavalrymen entered Chambersburg and demanded $100,000 in gold or $500,000 in greenbacks. The residents of Chambersburg failed to raise the ransom, and McCausland ordered his men to burn the town. Flames destroyed more than 500 structures leaving more than 2,000 homeless. One resident died of smoke inhalation. Damage was estimated at more than $1.6 million. To make matters worse, many inebriated Confederate soldiers looted homes and abused civilians. Mobs of angry townspeople looking for retribution killed several Rebels.
Good Samaritans in the Rebel ranks helped citizens escape and save their valuables; a Confederate captain even ordered his company to douse the flames. One officer, Colonel William Peters, staunchly refused to take part in the burning. McCausland had him placed under arrest.
Chambersburg was the only Northern town the Confederates destroyed. The attack inspired a national aid campaign and spurred the Union Army to the aggressive approach that finally won the war.