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...

An overview of the Oregon Boundary Treaty of 1846, which set the boundary between British North America and the United States at the 49th parallel. Information on the treaty, the personalities involved, relevant images, and a map are...

A map of the western United States in 1840-1850 showing the Oregon Trail and Santa Fe, the two principal overland routes from Independence, Missouri, to the western territories and the Pacific. The map shows the territory boundaries,...

A map from 1872 of the United States used to illustrate the comparative area sizes of the states to other countries in the world. The map shows state and territory boundaries at the time (Dakota, Montana, Washington, Idaho, Wyoming,...

A map of the United States at the time of the Kansas-Nebraska Act (1854) which allowed settlers to determine whether or not slavery would be allowed in their territories. The map is color-coded to show the Free States (including...

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

A map of the United States and territories in 1821 after the Missouri Compromise, showing the Free States and territories, the Slave States and territories, and the transitional territories at the time. The map is color-coded to show the...

A map of the United States in 1850, showing the frontier line, indicate by the thick black line. The map shows the States added to the Union between 1840 and 1850, including Florida (1845), Texas (1845), Iowa (1846), Wisconsin (1848),...

A map of the United States in 1830 showing the states and territories, the joint-occupation with Britain in Oregon Country, and the British and Spanish possessions at the time. The map shows the westward expansion of the United States,...

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 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 of the United States during the Presidency of John Quincy Adams (1825&ndash1829) showing the States at the time, the Unorganized Territory of the Louisiana Purchase, and the Oregon Country under joint control with Great Britain.

A map of the United States in 1801. The map is color-coded to show the States and territory of the United States west to the Mississippi River, the British territories of Upper and Lower Canada, Rupert's Land, and the Bahamas, the French...

A map of the United States showing the growth of the nation from 1776-1867. 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 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 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 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 effects of the Compromise of 1850. The map is keyed to show the free states and slave states, and notes California admitted to the Union as a free state; the Nebraska Territory as free by the...

A map from 1904 of the United States showing the territorial acquisitions up to the Gadsden Purchase in northern Mexico in 1853. The map is coded to show the territory of the original United States and the Northwest Territory defined by...

A map from 1904 of the United States showing the territorial acquisitions up to the Gadsden Purchase in northern Mexico in 1853. The map is coded to show the territory of the original United States and the Northwest Territory defined by...

A map from 1912 of the United States showing the territorial acquisitions up to the Gadsden Purchase in northern Mexico in 1853. The map is color-coded to show the territory of the original United States and the Northwest Territory...