The literature on the Civil War is immense, but a great deal of it tends to center around describing the military battles, and travails, with less discussion of the political and civil goings on at the time.
As @Shewmaker mentioned, Doris Kearns Goodwin's "Team of Rivals" is superb. Imagine how Lincoln was perceived by the eastern intelligentsia at the time - uneducated self taught auto-didact from the backwoods of Kentucky and southern Illinois - what a terrible mistake he was accidentally elected, and now the southern states were all seceeding!
A whole platoon of eastern Union generals could not sort out how to begin to conquer the rebelling southern states - they all thought the key to winning was down the east coast. How little they knew - Grant realised very early in the war that the key was the control of the Mississippi river, and proved it early with the capture of Fort Henry and Fort Donnelson. And while the east was celebrating the defeat of the invading southern army at Gettysburg, Grant captured Vicksburg which opened the Mississippi River, and allowed midwestern grain to flow to overseas markets, and the Union Army to cross Tennnessee, capture Chattanooga, and Atlanta, and Sherman to ride into the Carolinas destroying the bread basket of the south. Grant finally stood at Appamattox for the Lee's surrender.
I am now rereading Ron Chernow's "Grant" which discusses in great length Grant's story and his feelings about slavery. In our modern era we find it almost impossible to understand how slavery was tolerated, but in the 1850s, people in the Northern and Southern States all grew up with slavery since before they were born. U S Grant was born on April 27, 1822 in Point Pleasant Ohio, to Jesse and Hannah Grant. Jesse and his older half brother were strongly tied to the abolitionist movements. After graduating from West Point, Ulysses S Grant was assigned to St Louis and there he met Julia, his wife, the daugher of a plantation owner, who owned over 300 slaves. It took over four years for Ulysses and Julia to finally wed: one can only imagine how the two families felt about each other - one slave owning, and one abolitionist. Indeed, Ulysses’s parents did not attend their son's wedding, in the home of his bride's slave owning parents, in St Louis.
As a side note, note that most of the men in the United States, born in the decades of the 1820 and 1830s and 1840s ended up serving in either the Union Army, or the Confederate Army. My great great grandfather and a great great uncle both served in regiments raised in Indiana, and fought for almost 4 years. I possess over a dozen letters written by campfires in Kentucky, Tennessee, Georgia, and South Carolina from 1862 to 1865 by a close relative in the 80th Indiana.
Another book about Grant that is considered excellent, is Grant's own autobiography, completed just months before his death and after two terms as the President of the USA. "Grant: Selected Memoirs and Letters" - it discusses at some length his experiences in the Mexican War of the early 1840s in which almost all of the major officers of the US Civil War learned their trade.
Another volume I enjoyed is "Days of Defiance: Sumpter, Seccession, and the Coming of the Civil War" by Maury Klein describing the fall of the Union into fateful, dreadful Civil War through the eyes of a British Journalist William Howard Russell.
It opens with a quote from Alexis de Tocqueville that we might be smart to remember right now.....
"There are two things that a democratic people will always find very difficult, to begin a war and to end it"
Another book about slavery in the USA is "White Cargo: The Forgotten History of Britain's White Slaves in America" by Jordan and Walsh. How did a nation so free of slavery, Britain in the 16th century, become enveloped in the slave trade?? It started with indentured slavery in Colonial America.
And finally, "Touched by Fire" by James M Perry about 5 Civil War veterans who went on to become Presidents of the United States - Ulyses S Grant, Rutherford B Hayes, James A Garfield, Benjamin Harrison, William McKinley.
The published estimates for dead in the American Civil War are about 620,000 - but one must remember those were soldiers, in uniform, on the military roles. How many civilian deaths also occured as a result of disease, economic losses, starvation, crimes due to lack of laws and police protection??
Some estimates are over 50,000 - but some think that is way too low - and estimate the total Civil War deaths as high as 850,000 which is twice that of WW II with 1/3 to 1/2 half the total civilian population.
Roughly 1 of every 16 men who lived in Indiana died - 25,000 deaths out of a population of ~400,000 men. Roughly 1 in every 13 who served during the Civil War came home with fewer than 4 limbs - they lost an arm, a leg, or more than one of each.... In Indiana the population was roughly 800,000-900,000 during the Civil War, versus 6.7 million today, with 25,000 lost to combat and disease. Several states had even higher losses...
I submit it is almost impossible to really understand and fully appreciate the Civil War even today. Most folks today have forgotten the sacrifices made by the Union Army's soldiers. When I read of my ancestors standing watch at night in the open in Kentucky in February with tempeatures in the "teens" it is really hard to imagine living in a tent in those conditions for weeks on end.
One last suggestion, "Ninety Eight Days: A Geographer's View of the Vicksburg Campaign" by Warren E Grabau - an extended discussion of the taking of Vicksburg - but it contains a lot of interesting materiel about the logistics of supplying a large horse drawn Army in the field, behind or surrounded by enemy lines. One division of infantry - 6000 men in the field - required about 18,000 pounds of food a day, every day - which had to be moved by horse drawn wagons over unpaved roads or no roads. Grant had roughly 70,000 men to provide for. The horses required 20 pounds of fodder a day, and each wagon had 4 to 6 horses..... Grant was not only a superb military tactician, having served in the quartermasters in the Mexican War, he was also superb in logistics - the feeding and supplying of an army in the field. Interesting book about the capture of Vicksburg.
A famous general, Omar Bradley, said "good generals study tactics, but great generals study logistics...."
Vicksburg did not celebrate the 4th of July for about 80 years subsequent to its surrender on July 4 1863