William Henry Hudson served on the United States Exploring Expedition, 1838-1842 (Senior commander Charles Wilkes), as midshipman on board the sloop of war Vincennes and Peacock . With a fleet of six vessels, the expedition was commissioned on a world voyage of hydrography and exploration that included forays into the Southern Ocean. The expedition was the first to delineate a substantial length of Antarctic coastline, enough to establish that immediately behind lay a landmass of continental size. The published charts of the expedition were the earliest to use the term Antarctic Continent.
From the guide to the William Hudson collection, 1841-1842, (Scott Polar Research Institute, University of Cambridge)
British Library Archives and Manuscripts Catalogue : Person : Description : ark:/81055/vdc_100000000622.0x0001ac