Extreme points are portions of a region which are further north, south, east, or west than any other. This is a list of extreme points in U.S. states, territories, and the District of Columbia.
Although many borders were initially defined by treaty or other agreement to be along a specific line of latitude or longitude, inaccuracies with surveying equipment/techniques caused the surveyed lines to deviate slightly from the true boundaries. Even as equipment/techniques improved, the initial surveyed line still remains the official border, which is why the extreme points may be either side of the agreed-upon line.
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