Answer:
Explanation:
"Westward expansion" redirects here. For trails in the American Old West, see Westward Expansion Trails.
Animated map of the territorial evolution of the United States (click to view full size image)
US Census Bureau map depicting territorial acquisitions and dates of statehood, probably created in the 1970s
US Census Bureau map depicting territorial acquisitions, 2007
The United States of America was created on July 4, 1776, with the Declaration of Independence of thirteen British colonies in North America. In the Lee Resolution of July 2, 1776, the colonies resolved that they were free and independent states. The union was formalized in the Articles of Confederation, which came into force on March 1, 1781, after being ratified by all 13 states. Their independence was recognized by Great Britain in the Treaty of Paris of 1783, which concluded the American Revolutionary War. This effectively doubled the size of the colonies, now able to stretch west past the Proclamation Line to the Mississippi River. This land was organized into territories and then states, though there remained some conflict with the sea-to-sea grants claimed by some of the original colonies. In time, these grants were ceded to the federal government.
The first great expansion of the country came with the Louisiana Purchase of 1803, which doubled the country's territory, although the southeastern border with Spanish Florida was the subject of much dispute until it and Spanish claims to the Oregon Country were ceded to the US in 1821. The Oregon Country gave the United States access to the Pacific Ocean, though it was shared for a time with the United Kingdom.[1] The annexation of the Republic of Texas in 1845 led directly to the Mexican–American War, after which the victorious United States obtained the northern half of Mexico's territory, including what was quickly made the state of California.[2] However, as the development of the country moved west, the question of slavery became more important, with vigorous debate over whether the new territories would allow slavery and events such as the Missouri Compromise and Bleeding Kansas. This came to a head in 1860 and 1861, when the governments of the southern states proclaimed their secession from the country and formed the Confederate States of America. The American Civil War led to the defeat of the Confederacy in 1865 and the eventual readmission of the states to the United States Congress. The cultural belief in the manifest destiny of the United States provided a strong impetus for westward expansion in the 19th century.
