Dueling officially fell out of fashion during the Antebellum period, but it remained pretty important extra-legally. Most states made laws prohibiting duels in most, if not all circumstance, but they continued, nevertheless. One of the important things to remember about the South is that they were really good at making laws that nobody followed.

Nevertheless, dueling was very important to Southern masculinity, especially if you were a planter. Dueling existed among the lower classes, but it was far less of a concern. Dueling was part of their stratified society, so you could only duel with people that were socially equal with you. Which is not to say that they were without honor, but honor was tied to land ownership, so poor people without land were not on the same level, unlike yeomen who could, and occasionally did, fight on equal footing with planters. In the same way that a man could defend his house, he could and should defend his honor. Without honor, how would other people know that a man could be trusted and dealt with? Furthermore, a slight on a planter could conceivably hurt the honor of all the planters. Since planters were always concerned with their position in society, they dealt severely with problems with honor. Honor itself is a public phenomenon, i.e. it is conferred by other people onto you. A man can't just declare himself honorable, it has to be conferred on him by the people around him. A public slight, therefore, was a very serious matter, one that only an apology or a duel could solve. Announcements that duels were planned appear frequently in newspapers across the South, so that everyone would know that it was happening, in spite of the laws.

That being said, there was a large contingent of people that opposed dueling. In my own work I've used a lot of petitions that can be found here and there are bunches of them that protest the frequency of dueling before the 1830s. Exactly how many people opposed dueling is hard to know, but it was enough that the aforesaid laws were passed.

Sources: Bertram Wyatt Brown, Southern Honor, Stephanie McCurry, Masters of Small Worlds, and the petitions mentioned earlier