This collection of previously unpublished diaries and correspondence between Maj. William Medill and older brother Joseph, one of the influential owners of the Chicago Tribune, illuminates the Republican politics of the Civil War era. The brothers correct newspaper coverage of the war, disagree with official military reports, and often condemn Lincoln administration policies. When shots were fired at Fort Sumter, the Medills mobilized, unaware how their courage would be tested in the coming years.

In “The Most Complete Political Machine Ever Known,” Paul Taylor examines the Union League movement. Often portrayed as a mere footnote to the Civil War, the Union League’s influence on the Northern home front was far more important and consequential than previously considered. The Union League and its various offshoots spread rapidly across the North, and in this first comprehensive examination of the leagues, Taylor discusses what made them so effective, including their recruitment strategies, their use of ostracism as a way of stifling dissent, and their distribution of political propaganda in quantities unlike anything previously imagined. By the end of 1863, readers learn, it seemed as if every hamlet from Maine to California had formed its own league chapter, collectively overwhelming their Democratic foe in the 1864 presidential election.

Among collections of letters written between American soldiers and their spouses, the Civil War correspondence of William and Jane Standard stands out for conveying the complexity of the motives and experiences of Union soldiers and their families. The Standards of Lewiston in Fulton County, Illinois, were antiwar Copperheads. Their attitudes toward Abraham Lincoln, “Black Republicans,” and especially African Americans are, frankly, troubling to modern readers. Scholars who argue that the bulk of Union soldiers left their families and went to war to champion republican government or to wipe out slavery will have to account for this couple’s rejection of the war’s ideals.

On March 9, 1862, the USS Monitor and CSS Virginia met in the Battle of Hampton Roads—the first time ironclad vessels would engage each other in combat. For four hours the two ships pummeled one another as thousands of Union and Confederate soldiers and civilians watched from the shorelines. Although the battle ended in a draw, this engagement would change the nature of naval warfare by informing both vessel design and battle tactics. The “wooden walls” of navies around the world suddenly appeared far more vulnerable, and many political and military leaders initiated or accelerated their own ironclad-building programs.

Richard M. Reid’s introduction captures the ways the war dramatically reconfigured the American medical landscape. Prior to the war, the medical community was badly fragmented, and elite physicians felt undervalued by the American public. The war offered them the chance to assert their professional control and to make medicine more scientific and evidence-based. The introduction also includes an extensive historiographical analysis of Civil War medicine and situates Wilder’s recollections in the changing direction of the field.

The 27th United States Colored Troops (USCT), composed largely of free black Ohio men, served in the Union army from April 1864 to September 1865 in Virginia and North Carolina. It was the first time most members of the unit had traveled so far from home. The men faced daily battles against racism and against inferior treatment, training, and supplies. They suffered from the physical difficulties of military life, the horrors of warfare, and homesickness and worried about loved ones left at home without financial support. Yet their contributions provided a tool that allowed blacks with little military experience, and their families, to demand social acceptance and acknowledgment of their citizenship.

In the summer of 1862, as Union morale ebbed low with home front division over war costs, coming emancipation, and demoralizing battlefield losses, 24-year-old William White Dorr enlisted as a lieutenant in the 121st Pennsylvania Volunteers, a new Union regiment organizing in Philadelphia. His father, the Reverend Benjamin Dorr, rector of Christ Church, Philadelphia, strived to prevent divisions in his congregation from sundering that Episcopal church historically tied to the nation’s founding.

The story of the American Civil War is not complete without examining the extraordinary and influential lives of Jessie Frémont, Nelly McClellan, Ellen Sherman, and Julia Grant, the wives of Abraham Lincoln’s top generals. They were their husbands’ closest confidantes and had a profound impact on the generals’ ambitions and actions. Most important, the women’s own attitudes toward and relationships with Lincoln had major historical significance.

In 1861, Lt. Col. William Hoffman was appointed to the post of commissary general of prisoners and urged to find a suitable site for the construction of what was expected to be the Union’s sole military prison. After inspecting four islands in Lake Erie, Hoffman came upon one in Sandusky Bay known as Johnson’s Island. With a large amount of fallen timber, forty acres of cleared land, and its proximity to Sandusky, Ohio, Johnson’s Island seemed the ideal location for the Union’s purpose. By the following spring, Johnson’s Island prison was born.

The Union states of what is now the Midwest have received far less attention from historians than those of the East, and much of Michigan’s Civil War story remains untold. The eloquent letters of James W. King shed light on a Civil War regiment that played important roles in the battles of Stones River, Chickamauga, and Missionary Ridge. King enlisted in the 11th Michigan in 1861 as a private and rose to the rank of quartermaster sergeant. His correspondence continues into the era of Reconstruction, when he tried his hand at raising cotton in Tennessee and Alabama and found himself caught up in the social and political upheavals of the postwar South.