Packaging Corporation of America (PCA) is a U.S. containerboard and corrugated packaging company. PCA produces containerboard — linerboard and corrugating medium — at ten mills, then converts that board into corrugated boxes at 91 plants across the U.S. Customers use these boxes to ship, store, and display goods across food and beverage, e-commerce, retail, agriculture, and industrial end markets. PCA's integrated model, from raw fiber to finished box, is central to its cost structure and margins. PCA has roughly 12,000 customers, with about 70% of corrugated sales going to regional and local accounts served within a ~150-mile radius of each plant. PCA also runs a smaller Paper segment, producing uncoated freesheet paper at a single mill in Minnesota, though this business faces secular decline as electronic communication displaces paper demand. PCA's earnings are driven by box prices, which are partially indexed to published containerboard price indices, and by volume, which tracks U.S. economic activity. Fiber and energy are the largest input costs; PCA self-generates roughly 62% of its packaging mill energy from pulping by-products. PCA grows primarily by expanding its converting network and improving mill efficiency, including a 2025 acquisition of two containerboard mills and eight converting plants from Greif for $1.8B. PCA is also investing ~$250M in gas turbines at two mills to reduce purchased electricity costs.