The most widely used map in the USA today for teaching geography is the Mercator projection map. This popularity is surprising, given the fact that Mercator constructed the map as a navigational aid. It may work well for sailors, but as an education tool it is markedly flawed because it distorts the actual size and relationship of land masses.
When the Mercator projection was created in 1569, the custom among map-makers was to place their own country—in this case, Germany—at the center of the map. The Equator is placed 2/3 of the way down the map rather than halfway down. This arrangement depicts Europe as being larger than South America. In reality, South America is almost twice the size of Europe. Alaska appears to be three times larger than Mexico, although Mexico actually is larger than Alaska. On a Mercator map, Greenland looks larger than China, even though China actually is four times larger than Greenland.
This map is a striking illustration that cartography is truly a mixture of art, science, personal viewpoint, and propaganda.For more details on the Mercator Map visit the link, What's Behind the Maps