These are all great answers. I definitely agree that Uncle Tom's Cabin depicts the scene of slavery leading up to the Civil War well. Since slavery was a large part of the Civil War, Uncle Tom's Cabin almost captures the essence of what the Civil War was all about.
I think that some of the best novels that depict everyday life before the Civil War, however, would be novels by Mark Twain. The Adventures of Tom Sawyer and The Adventures of Huckleberry Finn depict the lives of two boys growing up along the Mississippi River in the early 19th century. The portrayal or racism, slavery, and even everyday ideals for children of that time period such as friendship, school, jobs and working, etc. I believe it gives the reader a very good glimpse into what life was like pre-Civil War.
Hope this helps!
Uncle Tom's Cabin Harriet Beecher Stowe would be a great novel to try if you are interested in learning about the life of slaves in pro-slavery America. Kindred by Octavia E. Butler and Beloved by Toni Morrison are two more of classic American novels that depict the unfortunate lives of slaves in the slave trade.
If you are looking for a book that doesn't primarily focus on slavery during the civil war, then the national bestseller Gone With the Wind would be good to try. It focuses on the love life of a young and confident woman named Scarlett O'Hara in the 19th century.
The best novel that would depict the South leading up to the Civil War would be Uncle Tom's Cabin. Uncle Tom's Cabin follows many slaves as they try to fight for their freedom. This book showed many people around the country just how horrible slavery really was. This also enlarged the abolitionist movement, which lead up to the Civil War. Hope this helps you out!
Uncle Tom's Cabin is probably the most well known novel that speaks about slavery in the years leading up to the Civil War. The first installment was published about ten years before the start of the Civil War and the completed novel was published in 1852.
There are other great works (and some not so great works) published leading up to the Civil War that may give you some alternate views of what life was like at that time. Some deal with current times and others depict earlier times, but because they are all written in the time leading up to the Civil War you can see themes and ideals presented that were relevant at the time. The Scarlet Letter by Nathaniel Hawthorne (1850). Self-Reliance by Ralph Waldo Emerson (1851). Leaves of Grass by Walt Whitman (1855). The dime store novels of Kit Carson and Calamity Jane started being published in 1860. Melville was also writing during this time and Moby Dick has some interesting comments on slavery in pre-civil war times as well.