Pressed by Franklin's wife, Jane, Lady Franklin, and others, the Admiralty launched a search for the missing expedition in 1848. Prompted in part by Franklin's fame and the Admiralty's offer of a finder's reward, many subsequent expeditions joined the hunt, which at one point in 1850 involved eleven British and two American ships. Several of these ships converged off the east coast of Beechey Island, where the first relics of the expedition were found, including the graves of three crewmen. In 1854, explorer John Rae, while surveying near the Canadian Arctic coast southeast of King William Island, acquired relics of and stories about the Franklin party from local Inuit. A search led by Francis Leopold McClintock in 1859 discovered a note left on King William Island with details about the expedition's fate. Searches continued through much of the 19th century. In 2014, a Canadian search team led by Parks Canada located the wreck of Erebus west of O'Reilly Island, in the eastern portion of Queen Maud Gulf, in the waters of the Arctic archipelago. Two years later, the Arctic Research Foundation found the wreck of Terror south of King William Island. Research and dive expeditions at the wreck sites are currently ongoing.
In 1981, a team of scientists led by Owen Beattie, a professor of anthropology at the University of Alberta, began a series of scientific studies of the graves, bodies, and other physical evidence left by Franklin's men on Beechey Island and King William Island. They concluded that the men buried on Beechey Island most likely died of pneumonia and perhaps tuberculosis, and that lead poisoning may have worsened their health, owing to badly soldered cans held in the ships' food stores. It was later suggested that the source of this lead may not have been tinned food, but the distilled water systems fitted to the ships. However, studies in 2013 and 2016 suggested that lead poisoning was likely not a factor, and that the crew's ill health may, in fact, have been due to malnutrition – specifically zinc deficiency – possibly due to a lack of meat in their diet.
Cut marks on human bones found on King William Island were seen as signs of cannibalism. The combined evidence of all the studies suggested that the crewmen did not all die quickly. Hypothermia, starvation, lead poisoning, and diseases including scurvy, along with general exposure to a hostile environment whilst lacking adequate clothing and nutrition, killed everyone on the expedition in the years following its last sighting by Europeans in 1845.
The Victorian media portrayed Franklin as a hero despite the expedition's failure and the reports of cannibalism. Songs were written about him, and statues of him in his home town, in London, and in Tasmania credit him with discovery of the Northwest Passage, although in reality it was not traversed until Roald Amundsen's 1903–06 expedition. Franklin's lost expedition has been the subject of many artistic works, including songs, verse, short stories, and novels, as well as television documentaries.
The search by Europeans for a western shortcut by sea from Europe to Asia began with the voyages of Christopher Columbus in 1492 and continued through the mid-19th century with a long series of exploratory expeditions originating mainly in England. These voyages, when to any degree successful, added to the sum of European geographic knowledge about the Western Hemisphere, particularly North America, and as that knowledge grew larger, attention gradually turned toward the Arctic. Voyagers of the 16th and 17th centuries who made geographic discoveries about North America included Martin Frobisher, John Davis, Henry Hudson, and William Baffin. In 1670, the incorporation of the Hudson's Bay Company led to further exploration of the Canadian coasts and interior and of the Arctic seas. In the 18th century, explorers included James Knight, Christopher Middleton, Samuel Hearne, James Cook, Alexander MacKenzie, and George Vancouver. By 1800, their discoveries showed conclusively that no Northwest Passage navigable by ships lay in the temperate latitudes between the Pacific and the Atlantic Oceans.
In 1804, Sir John Barrow became Second Secretary of the Admiralty, a post he held until 1845, and began a push by the Royal Navy to complete the Northwest Passage over the top of Canada and to navigate toward the North Pole. Over the next four decades, explorers including John Ross, David Buchan, William Edward Parry, Frederick William Beechey, James Clark Ross, George Back, Peter Warren Dease, and Thomas Simpson made productive trips to the Canadian Arctic. Among these explorers was John Franklin, second-in-command of an expedition towards the North Pole in the ships Dorothea and Trent in 1818 and the leader of overland expeditions to and along the Arctic coast of Canada in 1819–22 and 1825–27. By 1845, the combined discoveries of all of these expeditions had reduced the relevant unknown parts of the Canadian Arctic to a quadrilateral area of about 181,300 km2 (70,000 sq mi). It was into this unknown area that Franklin was to sail, heading west through Lancaster Sound and then west and south as ice, land, and other obstacles might allow, to complete the Northwest Passage. The distance to be navigated was roughly 1,670 kilometres (1,040 mi).