Captain William L. Hudson was commander of the US ship Peacock, one of the vessels of the United States Exploring Expedition to the Pacific 1838-42, commanded by Commodore Charles Wilkes.

The journal begins on 20 August 1838 and is preceded by a list of the officers and scientific corps of the United States Exploring Expedition and correspondence relating to it. It continues to 8 August 1840 and includes copies of correspondence exchanged during the voyage. The journal and preceding papers fill 567 pages. On p.564 is a summary of the voyage showing the dates of arrival at various ports. Places visited in the Pacific were: The Tuamotu Islands, Tahiti, Samoa, Lord Howe Island, Tonga and Fiji.