Stephen W. Kearny

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.

Jefferson Davis, the future and sole president of the Confederate States of America, graduates West Point in 1828.

The Mississippi native is commissioned as a second lieutenant with the 1st Infantry Regiment, and is stationed at Fort Crawford, Wisconsin.

As the flood-prone site of the fort is deemed no longer inhabitable, the army decides to build a new fort on higher ground.

Major Stephen W. Kearny, commanding officer at this time, surveys the area and chooses a site for the new fort upon a hill near the Mississippi River's eastern bank.

The situation in Mexico City is chaotic.

Antonio López de Santa Anna, president once again, denounces both congress and his own subordinates in the executive branch for their lack of resolve in preparing the defense of the capital.

They, in turn, denounce him for his failures in battle.

On August 20, 1847, the Army of Occupation asks for the surrender of Mexico City, but the battle continues until September 13, 1847, when the last bastion of Mexican resistance falls during the famous Battle of Chapultepec.

During the battle, young cadets from the Mexican military academy, the Niños Héroes (or "boy heroes") leap to their deaths rather than surrender.

The United States victory marks the end of the war and the beginning of negotiations for peace.

The idea of incorporating Texas into the United States has gained support both in Texas and in the United States Congress since Texas attained its independence from Mexico.

Definitive action on the measure has been delayed for several years, however, because of the divisive issue of admitting another slave state into the United States and the likely prospect that annexation would provoke a war with Mexico.

In early 1845, the United States Congress passes a resolution in favor of the annexation of Texas, which prompts Mexico to sever diplomatic relations with the United States.

The Mexican congress had never ratified Santa Anna's secret treaty with the Texans, and to underscore its opposition to Texas's independence, the Mexican congress passes a law that retroactively annuls any treaties signed by a Mexican negotiator while in captivity.

Further aggravating the dispute is the fact that the Texans have issued a dubious territorial claim that expands the republic's southern and western boundary from the previously accepted Nueces River to the Rio Bravo del Norte.

By claiming all of the land up to the headwaters of the Rio Bravo del Norte, the Texans have more than double the size of their republic to include parts of present-day New Mexico, Colorado, Oklahoma, Kansas, and all of present-day western Texas.

U.S. President James K. Polk dispatches a special envoy, John Slidell, to Mexico City shortly after Texas is admitted to the Union as the twenty-eighth state, to settle the Texas boundary dispute and to arrange the purchase of California.

The Mexican president, José Joaquín de Herrera, had been willing to recognize an independent Texas but is under intense domestic pressure to reject United States annexation and Texas's expanded territorial claim.

As a result, he refuses to meet Slidell and begins reinforcing Mexican army units along the Rio Bravo del Norte.

Hostilities between Mexico and the United States begin on April 25, 1846, when several United States soldiers are killed in a cavalry skirmish with Mexican forces in the disputed territory.

Shortly after the two sides declare war, Santa Anna is recalled from exile in Cuba to once again lead Mexican troops against a foreign invasion.

The United States Army attacks Mexico on three fronts: one column, under General Stephen W. Kearney, occupies California and New Mexico; another column, under General Zachary Taylor, enters northern Mexico; and a third detachment, commanded by General Winfield Scott, lands at Veracruz and marches to Mexico City.

California and New Mexico fall with little bloodshed.

Northern Mexico is the scene of fierce battles between Taylor and Santa Anna's armies at Buena Vista.

Santa Anna initially strikes hard at the outnumbered United States forces, but he later abandons the battle and returns to Mexico City, prematurely claiming victory.