On May 17, 1841, the United States sailing vessel Porpoise anchors below the bluff of present-day Tacoma, and her officers name Commencement Bay. The Porpoise is part of the United States Exploring Expedition commanded by Lt. Charles Wilkes (1798-1877). She is, in the words of Murray Morgan, "224 tons, 88 feet long, two-masted, rigged as a brigantine, carrying sixty-five men and under the command of Cadwallader Ringgold" (Puget's Sound, 51).
The following day two boats were sent out from the Porpoise to explore the surrounding area. Midshipman Joseph Sanford described the site of the future Tacoma as "a range of low hills covered with splendid trees. A snow-covered range in the distance to the east, of which Mount Rainier is the loftiest peak" (Puget's Sound, 52).
Lt. Charles Wilkes led this first United States Navy expedition to explore the Pacific Ocean. The expedition's six vessels had set out from Norfolk, Virginia in 1838, with the charge of exploring and charting the Antarctic, the islands of the South and Central Pacific, as well as San Francisco Bay and the Oregon Country -- the Puget Sound region. By the time the expedition reached Puget Sound, three years had gone by. One of the ships had been lost, and Wilkes's harsh, unreasonable command (including the frequent use of the lash), and occasionally incompetent seamanship had produced general misery among the crew.
In the Puget Sound region the expedition encountered Natives as well as British subjects in the form of Hudson's Bay Company employees. One purpose was to establish an American presence (Wilkes and crew named many points of land and water) and to assess American interests. The Wilkes expedition both used and elaborated charts made by the British explorer George Vancouver (1758-1798), who had charted the region in 1792. Captain Vancouver and his crew were the first white men to see the area. (Spanish explorers had previously sailed past and mapped the outer coast, including the mouth of the Columbia River.)
The region was jointly occupied by Great Britain and the United States in accordance with the Treaty of Joint Occupation of Oregon, signed by Great Britain and the United States on October 20, 1818.