René-Robert Cavelier, Sieur de La Salle, claims for France all territory drained by Mississippi River from Canada to the Gulf of Mexico and names it Louisiana.
Timeline of the Louisiana Purchase
The Louisiana Purchase Timeline
New Orleans is founded.
France cedes New Orleans and Louisiana west of the Mississippi to Spain.
France cedes territories east of the Mississippi and north of New Orleans to Britain.
Treaty of Paris gives newly independent United States free access to the Mississippi.
Spain closes lower Mississippi and New Orleans to foreigners.
French Revolution begins.
Slaves revolt on Caribbean island of Saint Domingue, France's richest colony.
Spain reopens the Mississippi and New Orleans to Americans.
Napoleon Bonaparte seizes power in France.
Spain secretly agrees to return Louisiana to France in exchange for Etruria, a small kingdom in Italy.
President Jefferson names Robert Livingston minister to France.
Spain cedes Louisiana to France. New Orleans is closed to American shipping. French army sent to re-establish control in Saint Domingue is decimated.
Jefferson sends James Monroe to join Livingston (pictured third from left) in France.
Napoleon decides against sending more troops to Saint Domingue and instead orders forces to sail to New Orleans.
Napoleon cancels military expedition to Louisiana.
Foreign Minister Talleyrand tells Livingston that France is willing to sell all of Louisiana.
Monroe arrives in Paris and joins Livingston in negotiations with Finance Minister Barbé-Marbois.
Monroe, Livingston, and Barbé-Marbois agree on terms of sale: $15 million for approximately 827,000 square miles of territory.
Britain declares war on France.
Purchase is officially announced in United States.
U.S. Senate ratifies purchase treaty.
Spain formally transfers Louisiana to France.
France formally transfers Louisiana to United States.