Because the National Trail Systems Act of 1968 included very little funding for the acquisition of land along the Appalachian Trail corridor, between 1968 and 1978, only a small portion (61 miles) of the corridor had been federalized in the first ten years following passage of the Act. In 1978, this situation changed radically with the passage of the amended version of the National Trails Systems Act. 

The new amendment to the Act substantially increased funding for the acquisition of private land along the AT corridor, appropriating $30 million per year for three years beginning in 1979. According to historian Sarah Mittlefehldt, by 1981, the National Park service acquired almot 825 miles of the Trail's route (almost 40 percent) that had been in private hands at the beginning of 1978. Further, the amendment provided for the increase in width of the trail corridor from 200 feet to 1,000 feet.

The amendment also increased the role of the Appalachian Trail Conference (ATC) in the land acquisition process, by requiring the ATC to submit a report to the Secretary of the Interior "a comprehensive plan for the management, acquisition, development, and use of the Appalachian Trail." The ATC was also charged with identifying "all significant natural, historical, and cultural resources to be preserved," a provision in the Act that led to the acquisition of new lands for the Trail, including the ridgeline of Catawba Mountain in Virginia, the site of McAfee Knob and Tinker Cliffs, two of the most visited locations along the Trail.

One consequence of more aggressive land acquisition program, however, was growing resistance from private landowners, many of whom had been happy to grant easements to their local trail club for the use of their land, but who were not happy to be deprived of their property through a federal condemnation process. As a result, the ATC and the local trail clubs sometimes found that their longstanding relationships with local landowners foundered, in some cases permanently. In the end, however, the Acts of 1968 and 1978 made it possible for the Department of the Interior to acquire a robust trail corridor along the entire length of the Appalachian Trail, guaranteeing its survival for future generations of hikers.