I do a great deal of my "reading" through E-audiobook or CD audiobook. These are all available as free E-audiobooks via either Libby or Hoopla by way of your library card. I could provide a slightly different list if you want CD audiobooks.
The Union War by Gary Gallagher. Professor Gallagher makes the case that preservation of the Union was the main motivator for the war effort in the North.
These Honored Dead by Thomas A. Desjardin. A biography of the myth (as in great epic tale, not epic lie) of Gettysburg.
An Environmental History of the Civil War by Judkin Browning (from the Civil War America series). The author assigns basically each year of the war to a specific topic: Weather, disease, food, animals and terrain. For example, you'll learn why the mud of the Mud March is (likely) not the same as the everyday mud the kids track into the house and that the Confederate states were already importing hogs (pork being the protein of choice) and leather (not just for shoes but also to trick out horses) before the war.
To the Uttermost Ends of the Earth by Phil Keith. The hunt for and sinking of the CSS Alabama.
Star Spangled Scandal: Sex, Murder, and the Trial that Changed America by Chris DeRose. Probably more than you want to know about Dan Sickles, his trial for the murder of Philip Barton Key and his use of the temporary insanity defense.
Bloody Crimes: The Chase for Jefferson Davis and the Death Pageant for Lincoln's Corpse by James L. Swanson. The title says it all.
Capital Dames: The Civil War and the Women of Washington, 1848-1868, by Cokie Roberts. These are elite women like Adelle Cutts Douglas (Mrs. Stephen Douglas) and Elizabeth Blair-Lee.
Deadly Aim: The Civil War Story of Michigan's Anishinaabe Sharpshooters by Sally M. Walker. This is a YA book, but a good introduction to the topic if you think it would be interesting.
War on the Waters: The Union and Confederates Navies, 1861-1865, by James M. McPherson. The title says it all.
The Demon of Unrest by Erik Larson. An examination of the time between the election of Lincoln and the Confederates firing on Fort Sumter.
For Cause and Comrades: Why Men Fought in the Civil War by James M. McPherson. The title says it all.
This Republic of Suffering: Death and the American Civil War by Drew Gilpin Faust. How the massive number of deaths during the Civil War changed the way Americans dealt with and viewed death.
Gateway to Freedom: The Hidden History of the Underground Railroad by Eric Foner. Primarily about the Underground Railroad in New York state. Highlights Black involvement in securing their own freedom.
Midnight Rising: John Brown and the Raid that Sparked the Civil War by Tony Horwitz. The title says it all.
They Were Her Property: White Women as Slave Owners in the American South by Stephanie E. Jones-Rogers. The often overlooked role of white women in American slavery.
Our Man in Charleston: Britain's Secret Agent in the Civil War South by Christopher Dickey. The story of Robert Bunch who became British consul in Charleston in 1853.
Stealing the General: The Great Locomotive Chase and the First Medal of Honor by Russell S. Bonds. The title says it all.
Gunpowder Girls: The True Stories of Three Civil War Tragedies by Tanya Anderson. This is a YA book about the explosions at the Allegheny Arsenal, the Washington Arsenal and the Confederate States Laboratory in Richmond wherein the victims were young women. This is a nice introduction to the topic if you think it would be interesting.