On July 6, 1908, the Roosevelt set sail from New York City's 24th Street Pier. The ship would only travel as far north as Cape Sheridan on the Canadian Ellesmere Island, but two of the men on board—Robert Peary and his assistant of 22 years, Matthew Henson—were headed for a more ambitious final destination: The North Pole, which had yet to be reached by mankind. After leaving New York, the Roosevelt traveled to Etah in Greenland to meet up with a team of Inuit guides and sled dogs. Henson earned the trust of the Inuit people by learning their language and customs, earning himself the Inuit nickname "Maripaluk," or "Matthew the kind one." After anchoring the boat, six teams of men and dogs set out from Cape Crane. Five of these teams would drop off supplies along the way and turn around. For the final 133 miles, the expedition would consist of just Peary, Henson, four Inuit—Oatah, Egingwah, Seegloo, and Ookeah—and 36 sled dogs. It took them five days to travel those last 133 miles, and on April 6, 1909, just before noon, they became the first people to ever reach the North Pole.

Matthew Henson (center) and the four Inuit guides at the North Pole. Library of Congress//public domain.

They returned not to fanfare, but controversy. Another American explorer, Frederick Cook, was claiming to have already reached the North Pole the previous year. Eventually, Cook was revealed to be a fraud by two Inuit members of his expedition, and in 1911, a Congressional inquiry into the matter resulted in the Peary-Henson exploration being declared the first to reach the Pole.

Library of Congress//public domain.

Both Peary and Henson were members of the New York-based Explorers Club—Peary was an early member and the Club's third president, while Henson, who was African American, was admitted 30 years after reaching the Pole (which the club describes as an "honor long overdue"). The club's archives include over 100 stunning images taken during the adventure by Chief Engineer George Wardwell and photographer George Borup. They're displayed on lantern slides—small glass plates produced through a collodion wet-plate process that were hand-colored with watercolors and used to project images for large audiences. The photos are largely without captions or descriptions in the archives, but even without too much context, the images are striking.

A hand-drawn map of northern Greenland produced by Robert Peary.

Peary is pictured here with his daughter, Marie, who was born in Greenland to Peary's wife Josephine. Marie was often called the Snow Baby because she was the first Caucasian baby born in the Arctic.