Mark Monmonier

Much of the map’s leverage—a far better physical science analogy than power—stems from boundary lines that restrict where people can go or what they can do. Whoever draws the lines exerts enormous leverage insofar as delineating a boundary is far easier than erecting a fence or wall. And because maps work so well as navigation tools, they’ve earned a reputation for truthfulness and authority that makes us respect their lines, or at least feel a mite anxious when we consciously ignore them in a burst of exuberance, entitlement or outright civil disobedience. Another form of cartographic leverage occurs when boundaries devised for one purpose are adopted for something else—the mapmaker avoids the tedious tasks of stating goals and delineating lines that reflect the new goals, and the borrowed borders leverage the familiarity and prestige of the lines adopted.