Before the great Atlantic Ocean could be crossed, the English Channel had to be crossed, and it was in 1909 by Louis Bleriot, by the narrowest of margins with his crutches (necessary from an earlier accident). He did not have a single navigational instrument.
Next the Alps were conquered, then the Pyrenees and the Mediterranean Sea. Great cities were linked. The advent of war in 1914 ended the brief era of these pathfinders but their deeds had contributed to the prelude of the Golden Age of Aviation.
The Pathfinders book is one volume included in the Time-Life Epic of Flight series.