There were enormous economic benefits to discovering a waterway that would connect the Atlantic and Pacific Oceans.  Doing so would open access to trade with India and China in Asia.  After all, this was what Columbus had set out to do initially in 1492.  Virtually all of the commercial powers of Europe sought to discover this Northwest Passage.  The Spanish, Russians, Danes, and Italians all looked sent expeditions to discover the route.  Cortes, from Mexico, even sent expeditions up the Gulf of Mexico because the Spanish thought California was an island.  

The most active player in the pursuit for a Northwest Passage were the English. Most of the well known and successful explorers from that pursuit were English, including Sir Francis Drake, John Cabot, and Henry Hudson.  Finally, in 1850 the Englishman Robert McClure discovered the route that would connect the Atlantic and Pacific Oceans via the Arctic Ocean.