On October 16, 1864, the regiment, under General Sherman, began the historic “march to the sea”, arriving in Savannah, Georgia “in fine condition”. The regiment must have stayed in the Savannah area for a few months.
The 11th Iowa regiment was ordered to Atlanta joining General Sherman’s army at Neworth, Georgia. The regiment served the entire campaign, engaging in four battles. They first met the Confederate army at Kenesaw on June 15th, where they lost a man. In the skirmishes that followed on a daily basis, the regiment, which was part of the Iowa brigade, sustained heavy losses. Beginning on July 22nd in the siege of Atlanta, they were under fire nearly eight-one days. For sixteen of those days they engaged in battle. On the first of September, the last battle was fought in what was known as the Atlanta campaign.
Union Historical Company,Portrait and Biographical Album, History of Washington County, Iowa, its Cities and Towns, Mills & Company, publisher, 1880, pgs. 363-365.
 Ibid pg. 473
Isaac’s regiment was involved in the Meridian raid. Along with other Union troops, they disabled the Confederate’s locomotives, railroad bridges, trestle work and sawmills. 
 For more information, see: http://en.wikipedia.org/wiki/Battle_of_Meridian
Isaac signed a volunteer enlistment document on January 25, 1864.
“In the winter of 1863-64, special inducements were held out to the old soldiers to re-enlist, and Isaac was among the first to again offer his services for three years more. The veterans were all given a thirty-days’ furlough, during which time Isaac returned to his home to visit family and friends. When he left the South, returning home on his furlough, peaches were about as large as peas, but on his arrival in Washington County [Iowa], he found it very cold, and snow upon the ground.” 
“On the expiration of his furlough, Isaac again bid good-bye to his friends and rejoined his regiment at Camp McClellan, near Davenport. The regiment was soon afterward ordered to Cairo, and then to Paducah, Ky., and went into camp on the Tennessee River. While there the smallpox broke out, but Isaac escaped the loathsome disease. ” 
Portrait & Biography Album of Washington County, Iowa, Acme Publishing Company, Chicago, 1887, pg. 364-5.