The Eastern United States has experienced a remarkable history of disturbance and recovery over the past two centuries. Before European settlement, forests occupied most of the land area. From the mid-19th to early 20th century , harvesting for timber and to clear agricultural land reduced forest cover by more than 90% in many places. Throughout most of the rest of the 20th century, forest cover subsequently increased following the abandonment of marginal agricultural fields and active New Deal reforestation efforts.