The story of the Appalachians started almost half a billion years ago. The first British colonialists arrived to North America just 400 years ago and yet both events are connected and shaped the history of the United States. Without a series of orogenic cycles 490-300 million years ago, caused by the continental collision assembling the super-continent Pangaea and forming the geological roots of the Appalachians, maybe today there would be the United States of Canada, bordering to the south with the Spanish-American Empire.
The first British colonialists arrived to America in 1607 and were confined by the mountains to the Atlantic coastal plains. The parallel north-south trending ridges of the Appalachians, formed by tilted and folded layers, were a difficult terrain, not suited for permanent settlements and of no use to the first farmers.
Fig.1. Geological Map of Pennsylvania, published in 1858, showing the north-south trending ridges of the Appalachians mountains (source).
Only the French, settling from the North (territory later to become Canada), claimed the Appalachians, establishing a network of outposts for trading fur in the mountains. In the south Florida and the Great Plains were claimed by the Spanish crown as New Spain.
It seemed that the British were surrounded by both natural as political opponents. However the isolation soon provided decisive. The plains in the Great Appalachian Valley in eastern Pennsylvania provided fertile ground and the population of the colonies grow over time, unnoticed by the French and Spanish. Soon the British expanded westwards in search of new land. This led to a conflict between England and France above the control of the few gaps and mountain passes in the Appalachians. The English colonists were far more numerous and better supplied than the French, having direct access to the sea. The rugged, poorly accessible terrain of the Appalachians proved difficult to defend by the French and allied Indians and were eventually lost to the expanding British colonies.
After the end of the French-American War the English crown wanted to limit the colonization and new settlements to the area of the Appalachians, hoping so to avoid further conflicts with the remaining French and Spanish territories. However the unexpected result was a resentment among the British settlers in America. Colonialists became convinced that the crown didn´t care for the political future of the successful expanding colonies. Among other factors, this resentment will contribute to the later Revolutionary War, where the American colonies will declare their independence, leading in the end to the foundation of the United States of America.
ALESHIRE, P. (2008): The Extreme Earth - Mountains. Chelsea House Publishers: 144