President Thomas Jefferson buys the Louisiana Territory from France for $15 million. This doubles the size of the United States and provides a large area to the west of the country for expansion.
Explorers Lewis and Clark map out areas of the Louisiana Purchase and eventually reach the Pacific Ocean.
In the culmination of a long revolution, Mexico wins independence from Spain and takes control of the territories of New Mexico and California.
the 363-mile canal connects Buffalo and Albany New York, which then connects to New York City via the Hudson River. The Erie Canal links New York City to the Great Lakes, and thus the West. This begins a period of rapid canal development in the North and Northwest, revolutionizing domestic trade and transportation.
Congress passes a law to move Native Americans from the Southeast to the west of the Mississippi River.
Chief Justice John Marshall ruled that the Cherokees comprised a "domestic dependent nation" within Georgia and thus deserved protection from harassment.
Texan leaders want to declare independence from Mexico
Federal agents persuaded a pro-removal Cherokee chief to sign the Treaty of New Echota, which ceded all Cherokee land for $5.6 million and free transportation west. Most Cherokees rejected the treaty, but resistance was futile. Between 1835 and 1838 bands of Cherokee Indians moved west of the Mississippi along the so-called Trail of Tears. Between 2,000 and 4,000 of the 16,000 migrating Cherokees died.
Mexican troops attack the Alamo Mission killing all but two Texans. This spurs the Texans on in the Texas Revolution.
Antonio Lopez de Santa Anna's Mexican force of 4,000 troops lays siege to the town of San Antonio, where 200 Texans resist, retreating to an abandoned mission, the Alamo. After inflicting over 1,500 casualties on Santa Anna's men, the defenders of the Alamo are wiped out on March 6, 1836. The Alamo becomes a symbol of the Texans' determination to win independence.
The Cherokee Nation is forced to march from the east coast to Oklahoma. Many thousands die along the way.
People begin to travel west in wagon trains on the Oregon Trail. Around 300,000 people would take the trail over the next 20 years.
Journalist John O'Sullivan first uses the term "Manifest Destiny" to describe the westward expansion of the United States.
The United States officially claims Texas as a state, eventually leading to the Mexican-American War.
After James K. Polk becomes President of the United States in January, Congress passes a measure approving annexation, trusting Polk to oversee Texas' admission more effectively than John Tyler would have.
Texas is officially granted statehood and becomes the 28th state.
After experiencing religious persecution, the Mormons move to Salt Lake City, Utah.
England signs the Oregon Treaty handing over the Oregon Territory to the United States.
A war fought over the rights to Texas. After the war, the United States paid Mexico $15 million for land that would later become California, Texas, Arizona, Nevada, Utah, and parts of several other states.
Polk was waiting for Mexico to strike the first blow. He then hears of these attacks and declares the Mexican War begun.
James Marshall discovers gold at Sutter's Mill. Soon word is out and people rush to California to strike it rich.
An American carpenter finds gold at the base of the Sierra Nevada Mountains, sparking a gold rush which brings tens of thousands of new settlers to California, establishing towns and cities, and accelerating the drive toward statehood.
They move to California to find gold
Under the Compromise of 1850, engineered by Henry Clay, California is admitted to the Union as a free state.
The Pony Express begins to deliver mail
The Transcontinental Railroad is complete and the Pony Express shut downs. The railroad rapidly affects the ease of western settlement, shortening the journey from coast to coast, which took six to eight months by wagon, to a mere one week's trip.
Arizona, the last of the 48 contiguous United States, is admitted to the Union, completing the century-long process of conquering and organizing the American West.