Rapid English colonial expansion east of the Appalachians (17th–18th centuries) triggered profound ecological transformation:
Vast forests cleared for agriculture, timber, and fuel. By 1850, >60% of original forest cover removed in many areas. Consequences: soil erosion, habitat fragmentation, altered microclimates, disrupted water cycles.
Habitat loss and overhunting drove extinctions: Passenger Pigeon (1914), Carolina Parakeet (1918), Eastern Elk, Eastern Cougar. Many more species extirpated regionally.
Tobacco and cotton monocultures exhausted nutrients; erosion stripped topsoil. Abandoned "worn-out" lands became widespread by early 1800s.
Mill dams, millraces, and drainage ditches fragmented rivers; wetlands drained for farming; anadromous fish runs (shad, salmon, sturgeon) blocked.
Commercial hunting for meat, hides, feathers (e.g., deer, beaver, waterfowl) depleted populations. Market hunting supplied cities and export trade.
Iron furnaces, tanneries, sawmills discharged toxins (heavy metals, tannins, sawdust) into streams. Urban centers (Philadelphia, Baltimore) lacked sanitation—cholera, typhoid outbreaks.
These changes set the stage for the 19th-century conservation movement (Pinchot, Muir, Roosevelt) and modern restoration ecology. The region's current "reforested" landscape is largely secondary growth on abandoned farmland.