In 1836, the U.S. government authorized a major naval surveying and exploring expedition to the Pacific and South Seas. This decision set the stage for a voyage that combined navigation and commerce goals with large-scale scientific collecting, including botany.
On August 18, 1838, the squadron left Hampton Roads (Norfolk area), Virginia, under Lieutenant Charles Wilkes. The ships carried naval crews along with a scientific corps that collected and documented plants as the voyage moved through many island and coastal environments.
As the expedition worked its way across the Atlantic and down the coast of South America, its botanists and assistants collected, pressed, labeled, and stored plant specimens. This routine—field collecting plus careful documentation—was essential because specimens had to survive long sea passages and still be useful for later study.
In early 1840, Wilkes’s ships traced long stretches of the Antarctic coast, work later credited with establishing Antarctica’s existence as a continent. While this was not a botanical milestone, it shows the expedition’s broader scientific reach and the demanding conditions under which collections and records were still maintained.
Across 1840–1841, the expedition surveyed and visited many South Pacific island groups. These stops allowed botanists to collect in habitats with high endemism (many species found nowhere else), building a major comparative set of Pacific plants for U.S. science.
In April 1841, the expedition left Honolulu and sent ships toward the Pacific Northwest. This leg mattered for botanical collecting because it shifted the focus from tropical island floras to temperate rainforests and coastal ecosystems in Oregon Country.
On July 18, 1841, USS Peacock wrecked while trying to cross the hazardous bar at the mouth of the Columbia River. The loss disrupted expedition logistics in the Pacific Northwest, but the work continued using other vessels—showing how fragile a collecting program could be when ships, storage space, and instruments were at risk.
In 1841, Wilkes’s party surveyed parts of Puget Sound and the Columbia River region and produced influential mapping of the Oregon Territory. Expedition scientists documented plants and other natural resources, linking botanical collecting with U.S. geographic knowledge and claims in the region.
On June 10, 1842, the flagship Vincennes arrived in New York, ending nearly four years at sea. Returning home was only the start of the scientific work: specimens and notes now had to be organized, safeguarded, and studied so the collections could be turned into published knowledge.
In 1844, the expedition’s five-volume Narrative was published, describing the route, observations, and results for a broad public audience. The Narrative helped keep attention on the voyage while specialized scientific reports—including botany—took much longer to prepare and publish.
The U.S. National Herbarium traces its beginnings to the Wilkes Expedition botanical collections accessioned in 1848, with botanists pressing about 50,000 specimens representing about 10,000 species. This anchored the expedition’s long-term legacy: Pacific and Pacific Northwest plant collections became a permanent reference set for identification, comparison, and later biodiversity research.
In 1854, major botany volumes from the expedition began to appear, including Asa Gray’s Botany: Phanerogamia (seed-bearing plants) and William D. Brackenridge’s work on ferns and related groups. These publications turned field specimens into named, described scientific records that other researchers could use.
On March 3, 1857, Congress appropriated money to move the Exploring Expedition collections from the Patent Office/National Institute custody to the Smithsonian and to build display cases. This was a turning point for long-term preservation: botanical specimens could be curated in a national institution rather than stored as a temporary government collection.
United States Exploring Expedition (Wilkes Expedition) Pacific Botanical Collections (1838–1842)