In the Western Theater, the Pacific current known as El Niño had a profound effect. When Bragg advanced into Central Kentucky in the fall of 1862, corn had died knee high & pastures were an expanse of dusty bristles. Streams & ponds were mere bare dirt. The corpses of Bragg's cavalry, supply animals & infantrymen littered the countryside; they literally dropped dead from heat prostration. At Perryville, a muddy waterhole was fought over as if life itself depended on holding that ground.
Ironically, El Niño had another card to play. As Bragg's retreating army straggled through Cumberland Gap, the earliest winter in memory set in with a vengence. Pickets were found frozen to death, still standing their posts. Bragg reported to Richmond that he did not know how many men he had or where they were.
At the same time, the union force holding Nashville was not immune to the dire effects of El Niño. The Cumberland River, which runs through Nashville, was the lifeline of the city. Hundreds of steamers nosed onto the bank at the end of Broad Street. Bachelorette parties climb up into their peddle bars on that spot, today. In 1862, the bachelorettes could have waded the river without the water overtopping their new cowgirl boots. Given the clapped out state of the Louisville & Nashville Rail Road & constant breaks caused by man & nature, the Nashville garrison was in real danger of being starved out.
Labor was requisitioned from farms surrounding Nashville. I have copies of requisitions for three men with tools, wheelbarrows & three days rations. Harnessing the labor of the 72,000 slaves in the counties surrounding Nashville was essential. The Nashville & Western Rail Road was driven 70 miles to the Tennessee River at Johnsonville. Not only did the self-liberated blacks build, maintain & man the logistic hub, after the Emancipation Proclamation, the 13th USCT Infantry guarded & kept the line open. El Niño played a vital part in enlisting Middle Tennessee slaves to support & take up arms for their own liberation.
The El Niño summer drought & record cold had a direct dramatic & dire effect on Western Operations throughout 1862-63. The description of Mother Bickerdyke's fight to keep thousands of sick & wounded men alive when an arctic front swept over Look Out Mountain is epic. The Mississippi River froze solid downnriver from Memphis. The weather reports from New England read like they were written by Steven King.
In November 1864, after the slaughter at Franklin, John Bell Hood's grieving army dug in on the hills above Nashville. They could clearly hear the jolly calliope music played for the three daily performances of a circus. Bitter, damp cold set in. Thousands of soldiers reported to Confederate hospitals almost blind from eye irritation. The only way to stay even remotely warm was to huddle around smoky wet wood fires.
Just as Union General Thomas was about to order an assault on Hood's army, a front blew in. Driving rain was followed by freezing rain was followed by plunging temperatures. Every twigg, blade of grass & rock was encased in cristal clear ice. Out in the black starless night, it sounded like dinosaurs were grazing through the trees. The next morning, the entire world was a Venetian chandelier. Out in the open, the men of the Army of Tennessee must have been equal parts dazzled & appalled.
In Nashville, the circus bought a half page ad announcing an indefinite extension of their engagement. More than twenty acts would perform three times a day. General Thomas had no choice but to delay his attack order. Thomas had been undercut by disparaging reports sent by General Scofield, an exasperated Grant put Black Jack Logan on a train with orders to supersede Thomas.
In typical El Niño driven Middle Tennessee weather, a warm front blew up from the gulf & the Crystal wonderland made way for pleasant temperatures. While still on his train, Logan learned that his dream of an army command was not to be. Smashed by two days of George Thomas' signure attacks, Hood's men fled south to the Tennessee River. An inspector general reported that the men gathered on the south bank of the Tennessee were nothing but an unarmed mob. El Niño had conspired with Generals Rosecrans, Grant & Thomas to utterly defeat the Army of Tennessee.