Far from what everyone expected, the first battle of the Civil War took a long time. Specifically, it lasted for 90 days, making senators and the civilians packed lunches carried in picnic baskets to watch the battle. No one thought that the battle would turn out as serious as it did. They soon realized that the battle isn’t a simple one that can be watched over picnic lunches.
Source: https://www.wearethemighty.com/mighty-history/first-battle-of-the-civil-war/