August 18, 1807: Robert Fulton and Robert Livingston Demonstrate the Speed of the Clermont Fulton and Livingston demonstrate the power of the steamboat by traveling from New York City up the Hudson River to Albany in 32 hours, a trip that would take a sailing sloop four days.

July 1821: Mexico Wins Independence from Spain In the culmination of a long revolution, Mexico wins independence from Spain and takes control of the territories of New Mexico and California.

October 26, 1825: The Erie Canal is Opened Completing construction begun in 1817, 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.

May 26, 1830: The Indian Removal Act is Passed The Indian Removal Act grants President Andrew Jackson the funding and authority to remove the Indians residing east of the Mississippi River, a goal he pursues with great zeal.

1832: Worcester v. Georgia In the case of Worcester v. Georgia, Chief Justice John Marshall ruled that the Cherokees comprised a "domestic dependent nation" within Georgia and thus deserved protection from harassment. However, the vehemently anti-Indian Andrew Jackson refused to abide by the decision, sneering "John Marshall has made his decision; now let him enforce it."

November 1835: The Texas Rebellion Begins A group of Texan leaders convenes to draw up a provisional government and declare independence from Mexico. Shortly after, fighting breaks out.

December 29, 1835: Treaty of New Echota is Signed 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.

March 6, 1836: The Alamo is Taken by Mexican Troops 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.

Spring 1844: John Tyler's Treaty Proposing the Annexation of Texas is Defeated in the Senate Congressmen wary of inciting further sectional conflict defeat the treaty for annexation. However, annexation becomes the major issue in the 1844 election.

February 1845: Congress Passes a Measure to Annex Texas 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.

July 4, 1845 Five months after the United States Congress votes to annex Texas, a Texas convention votes to accept annexation, despite the warning by the Mexican government that any agreement to join the United States will be equivalent to a declaration of war.

December 29, 1845: Texas is Admitted to the Union Texas is officially granted statehood and becomes the 28th state.

May 9, 1846: Polk Receives Word that Mexican Forces Have Ambushed Two American Companies Polk, waiting for Mexico to strike the first blow, hears of these attacks and declares the Mexican War begun. He demands that Congress vote for appropriations to carry out the war.

November 1846: The Donner Party is Snowbound Due to the erred advice of a guidebook, the Donner Party finds itself snowbound in the Sierra Nevada Mountains, and arrives at its destination in California only after turning to cannibalism to survive.

January, 1848: Gold is Discovered in California 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.

February 2, 1848: The Treaty of Guadalupe Hidalgo is Signed At the close of the Mexican War, the Treaty of Guadalupe Hidalgo cedes Texas, New Mexico, and California to the United States, which now controls land stretching all the way across North America.

September 9, 1850: California is Admitted to the Union Under the Compromise of 1850, engineered by Henry Clay, California is admitted to the Union as a free state.

May 10, 1869: The First Transcontinental Railroad is Completed The first transcontinental railroad is completed when the Union Pacific and Central Pacific railroads join their tracks at Promontory Point, Utah. 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.

June 1876: The Battle of Little Bighorn Colonel George Armstrong Custer and his men are wiped out by Sioux forces while attempting to control the Great Plains and confine all Indians to reservations. The battle symbolizes the strength of the Sioux resistance, and the US Army is forced to pursue a long war of attrition, rather than go head to head with the Sioux forces.

February 8, 1887: The Dawes Severalty Act is Passed The Dawes Act calls for the breakup of the reservations and the treatment of Indians as individuals rather than tribes. It provides for the distribution of 160 acres of farmland or 320 acres of grazing land to any Indian who accepted the act's terms, who would then become a US citizen in 25 years. The act is intended to help the Indians to integrate into white society, but in reality helps to create a class of federally dependent Indians.

December 29, 1887: The Massacre at Wounded Knee After an excited Native American fires a rifle shot, US Army troops massacre 300 Indians, including seven children. The massacre is the symbolic final step in the war for the West, and after Wounded Knee the Indians succumb to the wishes of the federal government, resigning themselves to reservation life.

February 14, 1912: Arizona is Admitted to the Union 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.