Nebraska in the American Civil War During the American Civil War ( 1861 – 65 ) , Nebraska was still a territory of the United States , not achieving statehood until two years after the War . Nebraska at the start of the Civil War . Antebellum Nebraska Territory was a slavery - free region . The Kansas - Nebraska Act of 1854 had established the 40th parallel north as the dividing line between the territories of Kansas and Nebraska . It had also repealed the Missouri Compromise of 1820 and allowed settlers in those territories to determine if they would allow slavery within their boundaries . Nebraska residents , many of them migrants from the Northern United States , chose to exclude slavery from their territory . Anti - secession feelings ran strong in the fledgling Nebraska Territory . Seward County was originally called Greene County , after a popular U . S . Army general from Missouri . But after General Greene joined the Confederacy , the county was renamed Seward for William H . Seward , Abraham Lincoln ' s Secretary of State . As the war began in April 1861 , Algernon Paddock was serving as the territorial secretary , the highest office . On May 15 , Alvin Saunders , a staunch Republican and supporter of President Lincoln , was sworn in as the formal Governor of Nebraska Territory . He served in that capacity throughout the war . Nebraska contributions to the war efforts . When the war started , U . S . Regular Army troops were withdrawn from Fort Kearny and Fort Randall to serve in more threatened areas , but at the increased risk to Nebraska settlers from Indian attacks . The Federal government requested that the Nebraska Territory form one volunteer regiment , with some companies supposed to stay behind to protect the territory . The territorial legislature met in special session in Omaha , and agreed to raise the requested local defense force . Thus , the 1st Regiment Nebraska Volunteer Infantry was formed in June and July 1861 , with the future governor of Nebraska and the Wyoming Territory , John Milton Thayer , as its first colonel . However , the promise was reneged , and the regiment was sent eastward in August to fight the Confederacy . Serving in the forces under Ulysses S . Grant , the 1st Nebraska Infantry participated in the successful attack on Fort Donelson in Tennessee and then fought at the Battle of Shiloh in April 1862 . It then participated in several minor engagements in Missouri and Arkansas . In October 1863 , the regiment was changed from infantry into cavalry , and was transferred to the frontier to keep the Plains Indians in check . It was mustered out of the Union Army in 1866 . Later in the war , some of the soldiers who served at Fort Kearny were former Confederates who had changed their allegiance to the Union , thus becoming " galvanized Yankees " . By the end of the Civil War , more than a third ( 3 , 157 ) of the men of military age in the Nebraska Territory had served in the Union army . In addition to the 1st Nebraska , the territory raised three other full regiments of cavalry , as well as several battalion s of militia . Thirty - five Nebraskans were killed in action during the civil War , while another 204 died of other causes , including disease and accidents . No Civil War battles or skirmishes were fought within the territorial borders of Nebraska , nor did Confederate troops attempt to invade the area . Today , several active people exist in the state of Nebraska that trace their organizational ancestry to Nebraska postbellum veterans groups , including the Grand Army of the Republic , the Sons of Union Veterans of the Civil War , and the Military Order of the Loyal Legion of the United States ( MOLLUS ) .