I know, at least in theory, what the Northwest Passage is, but I don't know any of the explorers mentioned in the lyrics, and I'm having trouble figuring out who they all are. To start with:
Ah, for just one time I would take the Northwest Passage
To find the hand of Franklin reaching for the Beaufort Sea
Who is Franklin? Did he find a sea route that involved passing through the Beaufort Sea (or at least look for one)?
Later on the song says:
Three centuries thereafter, I take passage overland
In the footsteps of brave Kelsey, where his Sea of Flowers began
Watching cities rise before me, then behind me sink again
This tardiest explorer, driving hard across the plain
Who is Kelsey? What was the overland route being described here, and was it really used for three centuries? Is "his Sea of Flowers" referencing something specific? Also, in terms of how long Europeans were crossing North America, it seems hard for him to be "this tardiest explorer" and still have discovered something that was in use for three centuries. Was he later in history than the other explorers mentioned, or is he referred to as tardy because overland travel is slower?
There are more explorers mentioned in another verse:
And through the night, behind the wheel, the mileage clicking west
I think upon Mackenzie, David Thompson and the rest
Who cracked the mountain ramparts and did show a path for me
To race the roaring Fraser to the sea
It's pretty easy to look up David Thompson, since the lyrics nicely included his whole name, but I'm not sure who Mackenzie and Fraser are. The lyrics seem to imply that they (or at least Fraser) discovered an overland route that was faster than Kelsey's. Did these guys make important discoveries, or are they just some of many explorers, who in this case happened to have names that suited the lyrics?
This isn't my usual area of expertise but a bit of a pet interest of mine, though I'm sure someone better qualified may come along!
The Northwest Passage was a theorised trading route that existed along the northern coast of North America that connected the Atlantic and the Pacific. Sir John Franklin is one of the best known of the explorers as, having led two missions to try and find the passage, he set out on a third journey with two vessels the HMS Terror and the HMS Erebus in 1845. The ships were last seen in Baffin Bay, and in spring 1847 they deposited an update on their progress at Victory Point.
On this account there are later notes stating that Franklin died in June 1847, and that the ships had been trapped in thick ice since September 1846, and thus abandoned in spring of 1848.
Multiple search expeditions were sent in the 19th century and various artifacts turned up, but there was no sign of any of the crew. As you can imagine, the crews of two ships that had seemingly vanished into thin air captured the imagination of many. There were rumours that the men had eaten each other - that's certainly the story I was told growing up. Bodies were found in the 1980's of three crew members and famously the wreckage of the ships were found in 2014 and 2016.
Henry Kelsey is unrelated to the Northwest Passage, but is a well-known explorer, believed to be the first European to have been to Saskatchewan. I believe the reference to tardiness is meant to be understood as referring to Rogers himself, not Kelsey, in this context. Rogers is commenting on the fact that he is the latest of these explorers to make these journeys across Canada, three centuries after Kelsey made them originally.
Mackenzie refers to Sir Alexander MacKenzie, an 18th/19th century explorer who was the first European to cross North America (excluding prior expeditions across Mexico) from east to west.
Fraser in the song specifically is referring to the Fraser River (hence 'race the roaring Fraser to the sea') but is named after Simon Fraser, who was a 19th century explorer who mapped much of British Columbia.
I think the choice of explorers is likely dual: their names suit the lyrics, but they are also some of Canada's most well-known explorers. Franklin's expedition and the mystery surrounding it, has inspired a significant amount of artwork, such as Wilkie Collin's play "The Frozen Deep," and numerous other fiction novels, music and paintings. There was also a recent television show, "The Terror." Kelsey is probably the least well-known, but is still well-commemorated in official naming and on commemorative memorabilia (coins, stamps.) MacKenzie is equally commemorated in schools but also the river, bay and mountain range named for him. Fraser's legacy can obviously be found on the river, in the bridge and the university.
Because we're discussing a smattering of historical events and time periods it's difficult to recommend any print sources that would cover them all effectively. That said, there are some fairly good sources available online.
The Dictionary of Canadian Biography has the biographies of Sir John Franklin, Henry Kelsey, Sir Alexander MacKenzie and Simon Fraser.
In terms of primary sources there:
For Mackenzie: The Journals of Alexander Mackenzie: Exploring Across Canada in 1789 & 1793 which can be found on Amazon.
For Franklin there's Papers relative to the recent Arctic expeditions in search of Sir John Franklin and the crews of H.M.S. "Erebus" and "Terror": presented to both Houses of Parliament by command of Her Majesty. (London, 1854)
For Kelsey, the Manitoba Historical Society has published Henry Kelsey's journal.
For Fraser, The letters and journals of Simon Fraser, 1806–1808 (Toronto, 1960)
Wanna know why this song irks me? It raises up John Franklin as the hero of the expedition. Truth is he died pretty much as soon as shit hit the fans, and it was Francis Crozier, the captain of the HMS Terror, who was second in command of the expedition (even though he was promised the lead position and then it was stolen by franklin), at which point Crozier lead the crews of both ships for several YEARS in the northern tundras to survive, even making contact with Inuit tribes there who became close enough with Crozier to even give him a localised name "Aglooka". The ultimate fate of Crozier is unknown, some claim he and his crew settled with the Inuit, or maybe they perished eventually in the frozen wastes, but we know for certain that for those years he fought harder, and more selflessly than Franklin ever did.