The Arkansas Post (; ), officially the Arkansas Post National Memorial, was the first European settlement located along the Mississippi River, in the Mississippi Alluvial Plain, and in the present-day U.S. state of Arkansas. In 1686, Henri de Tonti established it on behalf of Louis XIV of France for the purpose of trading with the Quapaw Nation.
The French, Spanish, and Americans, who acquired the territory in 1803 with the Louisiana Purchase, considered the site of strategic value. It was the capital of Arkansas from 1819 until 1821 when the territorial government relocated to Little Rock.
During the fur trade years, Arkansas Post was protected by a series of fortifications. The forts and associated settlements were located at three known sites and possibly a fourth. Some of the historic structures have been lost as the waterfront has been subject to erosion and flooding.
Since the 1950s, three archeological excavations have been conducted at Arkansas Post. Experts say the most extensive cultural resources at the site are archaeological, both for the 18th and 19th-century European-American settlements, and the earlier Quapaw villages. Here the French conducted the first documented Christian services in Arkansas.
Second location (Red Bluff)
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thumb|254px|Annie Hatley, Depiction of Arkansas Post in 1689, Arkansas State Archives, 1904
As a result of the Chickasaw raid and continued threats of attack, commander Ensign Louis Xavier Martin de Lino moved the post upriver. This was further from the Chickasaw territory east of the Mississippi, and closer to the Quapaw villages, the post's main trading partners and potential allies. This new location, about 45 miles from the mouth of the Arkansas, was called Écores Rouges (Red Bluff), at "the heights of the Grand Prairie". It was situated on a bend in the river, on higher ground than the previous site. The majority of the post's population remained French. This reality complicated Spain's effort for diplomacy. In 1772, Commander Fernando de Leyba was ordered to assert dominance over the local French and to reduce the amount of feasts and gifts they provided for the local Quapaw, as it was costing the colonial government too much. The Quapaw nearly came to blows with the Spanish, but eventually Commander Leyba conceded to previous practice and restored the goods, and conflict was avoided.
Fort Carlos III suffered from constant river erosion, so the Spanish relocated the military garrison to a site about half a mile from the waterfront and, in March 1791, built Fort San Estevan (renamed Fort Madison after the Louisiana Purchase). Fort San Estevan included a commandant's house, large barracks, storehouse and kitchen, all surrounded by a stockade.
In 1805, the U.S. government built a federal trading house at the north end of the post, operated by Jacob Bright. The location became a major frontier post for travelers heading west, with explorers such as Stephen Harriman Long and Thomas Nuttall passing through, although the government closed the federal house in 1810.
The Union victory relieved much of the harassment by Confederate forces on the Mississippi and contributed to the eventual victory at Vicksburg, Mississippi.
The former site of Arkansas Post was made into a state park in 1929. The park began with 20 acres donated by Fred Quandt, a descendant of German immigrants whose family still lives in Arkansas. In the following years, additional acreage was acquired and numerous improvements made with the support of Works Progress Administration labor. As with all National Historic Landmarks, Arkansas Post was administratively listed on the National Register of Historic Places on October 15, 1966.
Archaeology
In 1956–1957, Preston Holder conducted the first archeological excavations at the site. His team found remains of the eighteenth-century French colonial village within the area of the current memorial. The trenches discovered there were later identified as traditional French colonial residential building patterns of poteaux-en-terre. By this time, the remains of the 1752 La Houssaye fort, Fort Carlos III, 1790s Fort San Estevan, and Fort Hindman were all underwater in the former Arkansas River channel, an area then used as a navigation lake. No archeological evidence remains for those forts because of the erosion.