The Byrd Antarctic Expedition II Collection contains collected materials both from and about Byrd Antarctic Expedition II, some of which date before and after the Expedition. A candlestick from an expedition ship dates from 1884, and the rest of the collection dates from 1928 to 2010, with the bulk of materials dating between 1928 and 1935. The collection includes items such as correspondence from expedition members, artifacts from the United States Ship Bear and the expedition itself, a scrapbook, photocopies of the South Pole Radio News published by the expedition, an account of the trip to rescue Admiral Byrd from Advance Base by a crew member, advertisements by sponsors of the expedition, and postal covers.

The Raymond Fosdick Papers, dated 1926-1955 and 1979-1983, contain correspondence and American flags sent to Raymond Fosdick by Richard E. Byrd. Byrd had a practice of taking flags on his flights and expeditions then gifting them to friends and benefactors upon his return. Some of the correspondence accompanied the flags and some of the correspondence relates to other topics, such as the Fosdick Mountains. Materials created after Fosdick's death were received or collected by his family and also relate to Byrd and his relationship with Fosdick.

The United States Flag Flown at Finn Ronne Base, dated 1947 and 1989, contains an American flag that was used at Finn Ronne's base camp at Stonington Island during the Ronne Antarctic Research Expedition, 1947-1948, and stolen by the British. It also contains correspondence from Kevin Walton, a member of the British expedition, to Brian Shoemaker, a United States naval officer who participated in polar expeditions from 1966-1988 and met Walton at a gathering for polar explorers in 1989, regarding the history of that flag and its return to American ownership. There is also a letter sent by Shoemaker to the Byrd Polar Research Center Archival Program, after Walton gave him the flag, explaining the provenance of the donation.