Jules Dumont d'Urville discovers Adélie Land in Antarctica on January 21, 1840, claiming it for France.

The first days of the voyage from Hobart, Tasmania, had mainly involved the crossing of twenty degrees and a westerly current; on board there had been further misfortunes, including the loss of a man.

Crossing the 50°S parallel, they experienced unexpected falls in the air and water temperatures.

After completing the crossing of the Antarctic Convergence, on January 16, at 60°S they had sighted the first iceberg and two days later the ships found themselves in the middle of a mass of ice.

On January 20. the expedition had crossed the Antarctic Circle, with celebrations similar to crossing of the Equator ceremonies, and they sighted land the same afternoon.

The two ships slowly sailed to the West, skirting walls of ice, and on January 22, just before nine in the evening, some members of the crew disembarked on the north-westernmost and highest islet of the rocky group of Dumoulin Islands, at five hundred to six hundred meters from the icy coast of the Astrolabe Glacier Tongue of the time, today about four kilometers north from the glacier extremity near Cape Geodesie, and hoisted the French tricolour.

Dumont names the archipelago Pointe Géologie and the land beyond, Terre Adélie, for his wife.

The map of the coast drawn under sail by the hydrographer Clément Adrien Vincendon-Dumoulin is remarkably accurate given the means of the time.

Charles Wilkes's United States Exploring Expedition sights what becomes known as Wilkes Land in the southeast quadrant of Antarctica on January 25, 1840, claiming it for the United States, and providing evidence that Antarctica is a complete continent.

The Exploring Expedition, commonly known as the "Wilkes Expedition," includes naturalists, botanists, a mineralogist, taxidermists, artists and a philologist, and it is carried by USS Vincennes (780 tons) and USS Peacock (650 tons), the brig USS Porpoise (230 tons), the store-ship USS Relief, and two schooners, USS Sea Gull (110 tons) and USS Flying Fish (96 tons).

Departing from Hampton Roads on August 18, 1838, the expedition has stopped at the Madeira Islands and Rio de Janeiro; visited Tierra del Fuego, Chile, Peru, the Tuamotu Archipelago, Samoa, and New South Wales; from Sydney, Australia, sailed into the Antarctic Ocean in December 1839 and reports the discovery "of an Antarctic continent west of the Balleny Islands" of which it sights the coast on January 25, 1840.

The Wilkes expedition visits Fiji and the Hawaiian Islands after departing Antarctica.

In Fiji, the expedition kidnaps the chief Ro Veidovi, charging him with the murder of a crew of American whalers. and, in July 1840, two sailors, one of whom was Wilkes' nephew, Midshipman Wilkes Henry, are killed while bartering for food on Fiji's Malolo Island.

Wilkes' retribution is swift and severe.

According to an old man of Malolo Island, nearly eighty Fijians were killed in the incident.

Lieutenant Charles Wilkes, leading the United States Exploring Expedition, surveys the west coast of North America, including the Strait of Juan de Fuca, Puget Sound, the Columbia River, San Francisco Bay and the Sacramento River, in 1841.

He lands at Fort Nisqually, an important fur trading and farming post of the Hudson's Bay Company in the Puget Sound area, part of the Hudson's Bay Company's Columbia Department, on May 11, 1840.

Wilkes holds the first American Independence Day celebration west of the Mississippi River in what is now Dupont, Washington on July 5, 1841.

The Pugets Sound Agricultural Company (PSAC) had been formed in 1840 as a subsidiary of the HBC to meet its contractual obligations with the Russian-American Company in the RAC-HBC Agreement.

Fort Nisqually and Cowlitz Farm are attached to the new venture, though it remains staffed and managed by HBC personnel.

In 1841 mostly Métis families from the Red River colony are hired by the PSAC to become pastoralists and farmers upon its two stations.

After traveling overland to Fort Vancouver by James Sinclair, fourteen Métis emigrant families from the Red River colony choose Fort Nisqually as their final destination.

The United States Exploring Expedition, led by Lieutenant Charles Wilkes, passes through the Ellice Islands and visits Funafuti, ...

...Vaitupu in 1841.

...Nukufetau and ...

Captain Charles Wilkes employs hundreds of native Hawaiian porters and many of his men to haul a pendulum to the summit of Mauna Loa to measure gravity from December 1840 to March 1841.

Instead of using the existing trail, he has blazed his own way, taking much longer than he had anticipated.

The conditions on the mountain remind him of Antarctica.

Many of his crew suffer snow blindness, altitude sickness and foot injuries from wearing out their shoes.

The United States Exploring Expedition returns by way of the Philippines, the Sulu Archipelago, Borneo, Singapore, Polynesia and the Cape of Good Hope, reaching New York on June 10, 1842.

Lieutenant Charles Wilkes, after having completely encircled the globe (his is the last all-sail naval mission to do so), has logged some eighty-seven thousand miles and lost two ships and twenty-eight men.

Wilkes is court-martialed upon his return for the loss of one of his ships on the Columbia River bar, for the regular mistreatment of his subordinate officers, and for excessive punishment of his sailors.

A major witness against him is ship doctor Charles Guillou.

Wilkes is acquitted on all charges except illegally punishing men in his squadron.

Captain Charles Wilkes, commanding the Union frigate San Jacinto, seizes from the neutral British mail steamer Trent on November 8, 1861, two Confederate commissioners, James Murray Mason and John Slidell (law partner of Confederate Attorney General Benjamin) who seek the support of England and France for the cause of the Confederacy.

This unauthorized seizure sparks a storm of indignant protest from the pro-Confederate British aristocracy, which sympathizes with the southern plantation owners.

Commercial interests, which hope for cheaper raw materials, especially cotton, from an independent South, begin pro-war agitation.

The British government issues an ultimatum demanding an American apology and the release of Mason and Slidell.