What did this country do that caused alarm for the United States and especially farmers living west of the Appalachian Mountains?

Explanation:

Appalachia (/ˌæpəˈleɪtʃə, -leɪʃə, -lætʃə/) is a cultural region in the Eastern United States that stretches from the Southern Tier of New York State to northern Alabama and Georgia.[1] While the Appalachian Mountains stretch from Belle Isle in Canada to Cheaha Mountain in Alabama, the cultural region of Appalachia typically refers only to the central and southern portions of the range, from the Blue Ridge Mountains of Virginia, southwesterly to the Great Smoky Mountains. As of the 2010 United States Census, the region was home to approximately 25 million people.[2]

by using  production possibilities graph.  opportunity costs are key expenses in financial matters and are utilized as a part of registering money saving advantage investigation of a venture. such expenses, be that as it may, are not recorded in the record books but rather are perceived in basic leadership by processing the money costs and their subsequent benefit or misfortune.