A copy of the first map to portray the world as a globe has been bought for £545,600 at Christie's in London.
The price paid for the 1507 drawing - the first to label the New World as "America" - is a world record amount for a single sheet map.
London clock dealers Charles Frodsham and Co bought it, saying they were "over the moon" with their purchase.
The auction house also sold a recently discovered set of letters by the poet Percy Bysshe Shelley for £45,600.
The map was made German cartographer Martin Waldseemueller, who followed the teachings of Italian explorer Amerigo Vespucci.
Vespucci was the first to claim the New World was a separate continent - as opposed to Christopher Columbus, who thought it was part of Asia.
The name "America" was derived from Vespucci's first name, and the drawing was the first to distinguish North and South America and to show the Pacific Ocean.
The map, measuring just 18cm by 35cm, lay undiscovered in the stock of a European collector until two years ago.
He only realised the value of his possession after seeing a newspaper article about another Waldseemueller map.
Tom Lamb, director of Christie's book and manuscript department in London, described the find as "truly groundbreaking".
"This is one of the most exciting discoveries of my career, and represents the pinnacle in the history of map-making," he said.
Although Christopher Columbus landed in America before Vespucci, he was convinced the land mass was Asia.
It was Vespucci, after sailing there a few years later, who put forward the then-revolutionary argument that it was an entirely new continent.
In 1505 Rene II, the Duke of Lorraine, gathered a group of scholars at the Monastery of Saint Die des Vosges near Strasbourg, led by Waldseemueller, to create a new map of the world.
They worked from a French translation of Vespucci's voyages and, in 1507, published a work called "Cosmographiae Introductio" arguing the existence of a new land mass to the west.
They followed it within a month with the map showing the continent for the first time and clearly marking it "America".
"This simple sheet of paper holds so many new and anticipated discoveries, all created with an enormous leap of faith by a venerable geographer in a small town in Lorraine," Mr Lamb said.
The price smashed the previous world record for a map - £125,000 paid in 2002 for an Italian map of the world from the 1540s.
Shelley's letters, which had been expected to fetch £30,000, were written to Ralph Wedgwood, a member of the pottery family, between December 1810 and February 1811.
They provide an insight into the poet's views on atheism - opinions which resulted in his expulsion from Oxford University.
The letters had been destined for a car boot sale until the owner contacted the auction house.