What will become Nebraska had come under the "rule" of the United States for the first time after 1803, when the United States purchased the Louisiana Territory from France for fifteen million dollars.

President James Madison signs a bill in 1812 creating the Missouri Territory, including the present-day state of Nebraska.

Manuel Lisa, a Spanish fur trader from New Orleans, builds a trading post called Fort Lisa in the Ponca Hills in 1812, about a dozen miles north of what will become Omaha, after he had abandoned his trading posts on the Upper Missouri: Fort Raymond/Manuel in Montana and the original Fort Lisa in North Dakota.

The fort trades in furs, cattle, horses and land, and serves as a base from which Lisa acts as a sub-agent to neighboring tribes for the federal government.

With his wide trading network, Manuel Lisa has a unique role in relation to American Indian tribes.

He travels extensively among them to share agricultural products and build relations, as well as to promote trade.

According to one source, the influence of Manuel Lisa, exerted from Fort Lisa, is strong enough to hold all the native tribes of the Missouri River basin firmly in alliance with the United States during the War of 1812.

He organizes war expeditions from Fort Lisa against tribes on the Mississippi River allied with the British.

During the same period, he secures the allegiance of tribes along the northern Missouri River.

However, the War of 1812 will disrupt the fur trade with the natives for years.

The first steamboat to ply the Missouri River, the Western Engineer, piloted by Stephen Harriman Long, reaches Fort Lisa in 1819.

Aboard the ship are General Henry Atkinson and Captain Stephen Watt Kearny, both important to the future development of the American West.

Later forts in the Nebraska Territory will be named after them: Fort Atkinson and Fort Kearny.

Manuel Lisa spends the winter of 1819-20 at Fort Lisa with his third wife, Mary Hempstead Keeney.

He is in the company of Major Stephen Long, whose famous expedition encamps a mile and a half north of Fort Lisa.

Lisa returns in 1820 to St. Louis, where he will die within the year.

Fort Lisa likely influences the positioning of several nearby historically significant sites.

The American Fur Company, in competition, had established Cabanne's Trading Post two and one-half miles south in 1822.

The proximity of the posts, along with Fort Atkinson, will in turn influence the positioning of Cutler's Park, the Mormon Bridge, Fort Omaha, and Florence.

These establishments will attract the flow of Mormon Trail pioneers, which in turn will lead to the development of Kanesville, Omaha, Saratoga, and eventually all of North Omaha, as well as many further points in America's western expansion.

Major Joshua Pilcher, who had succeeded Lisa as president of the Missouri Fur Company, runs Fort Lisa until 1823, when he closes it after building Pilcher's Post downriver at what will become Bellevue.

Arikara raiders "attacked the Missouri Fur Company's Fort Recovery [a trading post for the Sioux] and killed two traders" in the beginning of 1823.

When Lewis and Clark reached Arikara settlements in 1804, the inhabitants had not shown hostility to the expedition, but in 1806, when an Arikara leader died during a trip to the United States capital, many Arikara believed that Americans were involved in his death.

Eventually, as a result of the growing activity of fur trading companies, contact between Arikara and white merchants had become more frequent, and skirmishes eventually followed.

The Sioux, both Yankton and Yanktonai east of the Missouri and Lakota on the west side, have for long been at war with the Arikara, interrupted by short truces on Sioux terms.

The Arikaras in question are living in a double village on the west shore of the Missouri, six or seven miles upstream from the mouth of Grand River.

A small creek separates the two fortified villages of earth lodges, each with a heavy frame of wood.

The United States responds with a combined force of two hundred and thirty soldiers of the 6th Infantry, seven hundred and fifty Sioux allies, and fifty trappers and other company employees under the command of Lieutenant Colonel Henry Leavenworth, Fort Atkinson, present-day Nebraska.

The seven hundred and fifty warriors are part Yankton and Yanktonai Sioux, part western Sioux from the Brule, the Blackfeet and the Hunkpapa divisions.

The native force receives promises of Arikara horses and spoils, and with the enemy's villages fallen new ranges will open for the Sioux.

The causes of the Arikara War are not well recorded, but the trading relationship of the Arikara with white traders is certainly a factor.

The Arikara live in permanent settlements for most of the year where they farm, fish and hunt buffalo on the surrounding plains.

However, this is insufficient to sustain them and they rely on being a center of trade with neighboring tribes to survive.

Ashley's expedition to directly acquire furs and pelts cuts out the Arikara in their role as trading middle-men and is thus a direct threat to their livelihood.

There is also the issue of their desire to have a trading post on their territory so that they can have easy access to manufactured goods.

They resent the fact that their long-time enemies, the Sioux, have such posts, but they do not.

Ashley had been asked to set up a trading post when he was in the area in 1822.

Not wishing to limit his operations by having to maintain a permanent base, Ashley had instead promised the Arikara that he would have the goods they asked for shipped to them directly from St. Louis.

Ashley had not made good this promise at the time of his 1823 expedition, and possibly never intended to.

A further source of resentment, although probably not a direct cause of the war, had been the death of the Arikara chief Ankedoucharo during a visit to Washington in 1806.

Ankedoucharo had died of natural causes, but it was widely believed among the Arikara that he was deliberately murdered.

The initial episode at the Arikara villages on June 2 reaches international level when some hinted, that the British Hudson's Bay Company is the mastermind behind it all.

The plot, so some believe, is to put a wedge between the American fur traders and the Arikaras.

The British deny this.

Colonel Leavenworth arrives at the Arikara villages on August 9 and commences the attack using his Sioux cavalry, but this is held off by the Arikara.

On August 10 Leavenworth orders an artillery bombardment.

This is largely ineffective, the shots falling beyond the villages, at which point Leavenworth orders an infantry attack.

Like the Sioux auxiliaries, the regular infantry also fails to break into the villages.

They leave the battlefield with some captured horses and laden with corn taken from the farming Indians' fields.

On August 11 Leavenworth negotiates a peace treaty.

"In making this treaty, I met with every possible difficulty which it was in the power of the Missouri Fur Company to throw in my way."

Fearing further attacks, the Arikara leave the village that night.

Leavenworth sets off to return to Fort Atkinson on August 15.

The Arikara village is burned behind him by resentful members of the Missouri Fur Company, much to Leavenworth's anger.

The US Army suffers the first casualties in the West during the Arikara War; seven people drown in the Missouri.

Stiff native resistance forces Ashley and Henry to abandon the posts they have established.

Henry retires from the late Manuel Lisa's company in 1824 and returns once more to lead mining.

Ashley devises the revolutionary rendezvous system, in which company agents are to meet independent trappers annually in a predetermined location at the end of spring to exchange trade goods for beaver pelts.

The first rendezvous is held in 1824.