The uses of maps are varied: they may serve as navigational aids, charters of ownership, symbolic forms of appropriation, or tools for political administration. They are also useful for the defense of diplomatic interests or serving military or commercial purposes, or may be valuable possessions and saleable goods in their own right. Likewise, they may be appreciated as works of art since they are often objects with an undeniable aesthetic appeal, and because mapmaking rests on complex technical skills.

The Spanish cartography of the New World has been studied in depth and is well documented. Some recent investigations offer a fairly complete account of their history. This chapter deals with a scientific project of great scope, closely linked to the Casa de Contratación, navigation, and the post of the pilot major: the drafting of a new map of the world or a Master Map. As indicated by its name in Spanish, it was a singular cartographic representation that was meant to serve as a point of comparison for all maps and as a model for all navigational charts. The idea was that, either in Seville or Madrid, the Crown would have a register and a faithful representation of the New World.

When the Crown appointed Amerigo Vespucci as the first pilot major, despite his lack of experience as a navigator, it ordered him to: