First map of the New World

The oldest surviving map that unambiguously shows locations in the New World is a chart drawn by Juan de la Cosa (Spain) in 1500. Juan de la Cosa was a veteran navigator and the captain/owner of the Santa María, one of the three ships that sailed with Christopher Columbus in 1492. The map shows the islands of the Caribbean and the northern coast of South America in some detail, but otherwise offers only a vague, conjectured outline of the Americas that extends to the left-hand margin of the map.

Juan de la Cosa's map is a fascinating snapshot of a period of rapid change in the world of cartography, showing influences from two distinct map-making traditions. The centre of the map shows Europe and western Africa in the style of a "portolan [or portulan] chart". These were early nautical charts that mark coastlines in great detail – with navigational landmarks, hazards and ports – but show very little of the geography farther inland. The world to the east of the Mediterranean, on the other hand, is depicted according to the traditions of the medieval Mappa Mundi, with vaguely defined landmasses illustrated with biblical scenes, myths and legends.

The New World is shown using a mixture of the two styles, with densely annotated portolan-style landmasses for the Caribbean and the coast of what is now northern Brazil (which had been explored) but only a roughly shaped mass of green for North and the rest of South America. The areas that are shown in detail suggest that Cosa drew on his own sketch maps and notes from his voyages with Christopher Columbus (in 1492–93, 1493–96 and 1498–1500), as well as reports from the voyages by the Pinzón brothers (1499) and John Cabot (aka Giovanni Cabotto; 1497).

There are several irregularities in scale in the western portion of the map, particularly the "English Coast", which appears to reproduce the section of Newfoundland explored by John Cabot, but vastly exaggerates its size. This is possibly because de la Cosa was working from descriptions or fragmentary sketch maps that had no accurate scale on them.