June 15

• The U.S. capital is moved from Philadelphia to Washington, DC.

November 17

• U.S. Congress meets in Washington, DC, for the first time.

• Gabriel Prosser, an enslaved African American blacksmith, organizes a slave revolt intending to march on Richmond, Virginia. The conspiracy is uncovered, and Prosser and a number of the rebels are hanged. Virginia's slave laws are consequently tightened.

March 4

• Thomas Jefferson is inaugurated as the third president in Washington, DC.

February 24

• Marbury v. Madison: Landmark Supreme Court decision greatly expands the power of the Court by establishing its right to declare acts of Congress unconstitutional.

Treaty signed May 2

• Louisiana Purchase: United States agrees to pay France $15 million for the Louisiana Territory, which extends west from the Mississippi River to the Rocky Mountains and comprises about 830,000 sq mi. As a result, the U.S. nearly doubles in size.
  Louisiana Purchase

May 14

• Lewis and Clark set out from St. Louis, Mo., on expedition to explore the West and find a route to the Pacific Ocean.

March 4

• Jefferson's second inauguration.

November 15

• Lewis and Clark reach the Pacific Ocean

March 4

• James Madison is inaugurated as the fourth president.
  James Madison

June 18, 1812

• War of 1812: U.S. declares war on Britain over British interference with American maritime shipping and westward expansion.

March 4, 1813

• Madison's second inauguration.

Aug. 1814

• British capture Washington, DC, and set fire to White House and Capitol.

Sept. 13–14, 1814

• Francis Scott Key writes Star-Spangled Banner as he watches British attack on Fort McHenry at Baltimore.

Dec. 24, 1814

• Treaty of Ghent is signed, officially ending the war.

March 4

• James Monroe is inaugurated as the fifth president.
  James Monroe

February 22

• Spain agrees to cede Florida to the United States.

• McCulloch v. Maryland: Landmark Supreme Court decision upholds the right of Congress to establish a national bank, a power implied but not specifically enumerated by the Constitution.

March 3

• Missouri Compromise: In an effort to maintain the balance between free and slave states, Maine (formerly part of Massachusetts) is admitted as a free state so that Missouri can be admitted as a slave state; except for Missouri, slavery is prohibited in the Louisiana Purchase lands north of latitude 36°30'.

March 5

• Monroe's second inauguration.

Dec. 19, 1777 – June 19, 1778

• Battle-weary and destitute Continental army spends brutally cold winter and following spring at Valley Forge, Pa.

Oct. 19, 1781

• British general Charles Cornwallis surrenders to Gen. George Washington at Yorktown, Va.

Sept. 3, 1783

• Great Britain formally acknowledges American independence in the Treaty of Paris, which officially brings the war to a close.

• Denmark Vesey, an enslaved African American carpenter who had purchased his freedom, plans a slave revolt with the intent to lay siege on Charleston, South Carolina. The plot is discovered, and Vesey and 34 coconspirators are hanged.

December 2

• Monroe Doctrine: In his annual address to Congress, President Monroe declares that the American continents are henceforth off-limits for further colonization by European powers.

Nov. 15

• Continental Congress adopts the Articles of Confederation, the first U.S. constitution.

March 2

• Gibbons v. Ogden: Landmark Supreme Court decision broadly defines Congress's right to regulate interstate commerce.

March 4

• John Quincy Adams is inaugurated as the sixth president.

• Erie Canal, linking the Hudson River to Lake Erie, is opened for traffic.
  View of Erie Canal by John William Hill, 1829

July 4

• Construction is begun on the Baltimore and Ohio Railroad, the first public railroad in the U.S.

March 4

• U.S. Constitution goes into effect, having been ratified by nine states.

March 4

• U.S. Congress meets for the first time at Federal Hall in New York City.

April 30

• Washington is inaugurated as president at Federal Hall in New York City.
  George Washington

March 4

• Andrew Jackson is inaugurated as seventh president.

• The court, made up of one chief justice and five associate justices, hears its first case in 1792.

• The nation's first census shows that the population has climbed to nearly 4 million.

May 28

• President Jackson signs the Indian Removal Act, which authorizes the forced removal of Native Americans living in the eastern part of the country to lands west of the Mississippi River.

• By the late 1830s the Jackson administration has relocated nearly 50,000 Native Americans.

• Nat Turner, an enslaved African American preacher, leads the most significant slave uprising in American history. He and his band of about 80 followers launch a bloody, day-long rebellion in Southampton County, Virginia. The militia quells the rebellion, and Turner is eventually hanged. As a consequence, Virginia institutes much stricter slave laws.
• William Lloyd Garrison begins publishing the Liberator, a weekly paper that advocates the complete abolition of slavery. He becomes one of the most famous figures in the abolitionist movement.

• Eli Whitney's invention of the cotton gin greatly increases the demand for slave labor.

March 4

• Jackson's second inauguration.

March 1

• Texas declares its independence from Mexico.

February 24 – March 6

• Texan defenders of the Alamo are all killed during siege by the Mexican Army.
  The Alamo

April 21

• Texans defeat Mexicans at San Jacinto

March 4

• Martin Van Buren is inaugurated as the eighth president.

• More than 15,000 Cherokee Indians are forced to march from Georgia to Indian Territory in present-day Oklahoma. Approximately 4,000 die from starvation and disease along the “Trail of Tears.”

March 4

• William Henry Harrison is inaugurated as the ninth president.

April 4

• He dies one month later and is succeeded in office by his vice president, John Tyler.

March 1

• U.S. annexes Texas by joint resolution of Congress

March 4

• James Polk is inaugurated as the 11th president

July–August

• The term “manifest destiny” appears for the first time in a magazine article by John L. O'Sullivan. It expresses the belief held by many white Americans that the United States is destined to expand across the continent.

June 15

• Oregon Treaty fixes U.S.-Canadian border at 49th parallel; U.S. acquires Oregon territory.

• The Wilmot Proviso, introduced by Democratic representative David Wilmot of Pennsylvania, attempts to ban slavery in territory gained in the Mexican War The proviso is blocked by Southerners, but continues to enflame the debate over slavery.

May 13, 1846

• Mexican War: U.S. declares war on Mexico in effort to gain California and other territory in Southwest.

Feb. 2, 1848

• War concludes with signing of Treaty of Guadalupe Hidalgo.

• Mexico recognizes Rio Grande as new boundary with Texas and, for $15 million, agrees to cede territory comprising present-day California, Nevada, Utah, most of New Mexico and Arizona, and parts of Colorado and Wyoming.

Jan. 24

• Gold is discovered at Sutter's Mill in California. The gold rush reaches its height the following year.

July 19–20

• Women's rights convention is held at Seneca Falls, N.Y.

March 5

• Zachary Taylor is inaugurated as the 12th president.
  Zachary Taylor

• Harriet Tubman escapes from slavery and becomes one of the most effective and celebrated members of the Underground Railroad.