For 20 years after its founding in 1825, the Hudson’s Bay Company’s trading post at Fort Vancouver was the major commercial and social center for the non-Indian peoples who were reaching the Pacific Northwest in increasing numbers. Although the HBC's owners and many employees were British, most of the arriving settlers were American. The Treaty of Oregon in 1846 settled the boundary between British and American territory at the 49th parallel, well north of the Columbia River, bringing Fort Vancouver under American jurisdiction, although recognizing the Hudson’s Bay Company’s title to its property. Two years later, spurred by petitions from settlers demanding protection after 14 people were killed in the 1847 attack on the Whitman mission, Congress officially established Oregon Territory and the army dispatched troops to the area.
First Artillery Companies L and M sailed from New York on the steamer Massachusetts in the fall of 1848, bound for the Columbia River by way of Cape Horn and Hawaii. They reached Fort Vancouver on May 13, 1849. That same day, on a bluff above the stockade of Fort Vancouver, the artillerymen raised an American flag on a fir tree cleared of its branches, and declared Camp Columbia in existence. The Hudson's Bay Company welcomed their arrival. The British firm wanted to establish good relations with the U.S. Army, which it hoped would prevent the increasing numbers of American settlers from encroaching on its property. The HBC permitted the army to build its facilities on the bluff above Fort Vancouver, and in the interim rented the artillerymen buildings located outside the HBC stockade.
Even with Hudson's Bay Company’s assistance, which included use of its sawmill to cut timber and helping the officers hire Indian laborers, building the new post went slowly. The California gold rush in the summer of 1849 led to a scarcity of labor and supplies, and drove prices up. When a regiment led by Colonel William W. Loring arrived in the fall after marching overland from Missouri, barracks were not yet ready. Many soldiers were housed across the Columbia at Oregon City, where they offended residents by their disorderly conduct, and some tried to desert to California and the gold rush. By the time construction was mostly completed in the spring of 1851, the name of the post had been changed to Columbia Barracks.
Later, partly to protect Hudson’s Bay Company property from the increasing trespasses by settlers, Col. Loring laid out a military reservation of 10,420 acres, four miles long on each side. The name was changed to Fort Vancouver Military Reservation. The good relations between the company and the army did not last as more settlers and soldiers, including officers with anti-British feelings, arrived in the area. The army began taking over HBC fields and demolishing its buildings to make way for army projects. By 1860, the Hudson' Bay Company abandoned its trading post, for which it was subsequently compensated by the United States government.
The army remained. Vancouver Arsenal was established at the post in 1859. In 1879, the post was named Vancouver Barracks, the name it retained in the twentieth century. Not until 1946, after the end of World War II, did the army declare most of Vancouver Barracks to be surplus.