A map of the western United States between 1836 and 1850 showing the Texas controversy and territorial adjustments at the time. The map is color-coded to show the unorganized territory of the Louisiana Purchase and the boundary line with...

Lewis and Clark National Historic Trail is approximately 4,900 miles long, extending from Pittsburgh, Pennsylvania, to the mouth of the Columbia River, near present day Astoria, Oregon. It connects 16 states. Today, visitors can follow...

Here's a map to show you when states were added to the Union. It also shows territories and when they were acquired.

This passionate essay provides an informative history of the battles between Northwest Indians and the US in the 1960s over fishing rights and broken treaties.

A brief look at the life of American explorer, Meriwether Lewis. Provides a historical map of the Oregon Territory, a portrait of Lewis, and a photograph from Little Belt Mountain.

A map of western North America between the opening of the Oregon Trail in 1832 to 1842, prior to the establishment of the Provisional Government of Oregon by American settlers in 1843. The map shows the boundary of the Oregon Country,...

A map of the Oregon Country showing the adjustments to the boundaries between 1818-1846, including the boundary established in 1818 to the east of the jointly controlled territory (Great Britain and the United States), the southern...

A map from 1911 of the United States showing the territorial acquisitions from the original states and territory established in 1783 to the Tripartite Convention of 1899 in which Germany and the United States divided the Samoan...

A map of the United States showing the growth of the nation from 1783-1867. The map is color-coded to show the thirteen original states, the territory acquired by conquest during the revolution and the Treaty of 1783, the Louisiana...

A map from 1904 of Oregon showing the capital of Salem, principal cities and towns, railroads, stage lines, mountains, rivers, and coastal features. "Oregon - Organized as a Territory in 1848; became a state in 1859. Area, 96,030 square...

A map from 1920 of the United States and its territories between 1783 and 1900 showing the nation's expansion and date of acquisition of each new territory or possession. The map is color-coded to show the progression from the original...

A map from 1898 of Oregon showing the capital of Salem, principal cities and towns, railroads, mountain systems, lakes, rivers, and coastal features. "Oregon, name derived from Spanish word signifying 'Wild Thyme,’ so called on account...

A map from 1885 of the United States showing the territorial growth from the original States and the Northwest Territory in 1783 to the Russian cession of Alaska in 1867. The map is color-coded to show the progression from the original...

A map from 1897 of the United States showing the territorial growth from the original States and the Northwest Territory in 1783 to the purchase of Alaska from Russia in 1867. The map is color-coded to show the progression from the...

A map from 1897 of the United States showing the territorial growth from the original States and the Northwest Territory in 1783 to the purchase of Alaska from Russia in 1867. The map is color-coded to show the progression from the...

A map from 1911 of the United States showing the territorial growth from the original States and the Northwest Territory in 1783 to the Gadsden Purchase of 1853. The map is color-coded to show the progression from the original thirteen...

A map from 1894 of the United States showing the territorial growth from the original States and the Northwest Territory in 1783 to the Russian cession of Alaska in 1867. The map is color-coded to show the progression from the original...

A map of the Oregon Country showing the adjustments to the boundaries between 1819-1846, including the southern boundary established by treaty with Spain in 1819, and the boundary dividing the territory between the United States and...

A map of the United States in 1803 showing the extent of the territory after the Louisiana Purchase from France. The map is color-coded to show the possessions of the United States, Great Britain, and Spain at the time, and shows the...

A map of the United States in 1821 showing the extent of the territory after taking control of Florida from Spain. The map is color-coded to show the possessions of the United States, Great Britain, and Spain at the time, and shows the...

A map showing the territory of the United States after the annexation of Texas in 1845, and the acquisition of the Oregon Country by treaty with Great Britain in 1846. The map is color-coded to show the possessions of the United States,...

A map of the United States in 1801 showing the extent of the territory at the time of the presidency of Thomas Jefferson. The map is color-coded to show the possessions of the United States, Great Britain, Spain, and France at the time,...

A good overview of the territorial expansion and its results that occurred in the United States over the first half of the 19th century.

An explanation of the difficulties the Republic of Texas encountered when deciding whether to join the Union. Also discusses President James Polk's efforts to expand the territories held by the United States, which brought him into...