The history of the lands that became the United States began with the arrival of the first people in the Americas around 15,000 BC. Numerous indigenous cultures formed, and many saw transformations in the 16th century away from more densely populated lifestyles and towards reorganized polities elsewhere. The European colonization of the Americas began in the late 15th century, however most colonies in what would later become the United States were settled after 1600. By the 1760s, the thirteen British colonies contained 2.5 million people and were established along the Atlantic Coast east of the Appalachian Mountains. After defeating France, the British government imposed a series of taxes, including the Stamp Act of 1765, rejecting the colonists' constitutional argument that new taxes needed their approval. Resistance to these taxes, especially the Boston Tea Party in 1773, led to Parliament issuing punitive laws designed to end self-government. Armed conflict began in Massachusetts in 1775.
Current territories of the United States after the Trust Territory of the Pacific Islands was given independence in 1994
In 1776, in Philadelphia, the Second Continental Congress declared the independence of the colonies as the "United States". Led by General George Washington, it won the Revolutionary War. The peace treaty of 1783 established the borders of the new nation. The Articles of Confederation established a central government, but it was ineffectual at providing stability as it could not collect taxes and had no executive officer. A convention wrote a new Constitution that was adopted in 1789 and a Bill of Rights was added in 1791 to guarantee inalienable rights. With Washington as the first president and Alexander Hamilton his chief adviser, a strong central government was created. Purchase of the Louisiana Territory from France in 1803 doubled the size of the United States.
Encouraged by the notion of manifest destiny, the United States expanded to the Pacific Coast. While the nation was large in terms of area, its population in 1790 was only four million. Westward expansion was driven by a quest for inexpensive land for yeoman farmers and slave owners. The expansion of slavery was increasingly controversial and fueled political and constitutional battles, which were resolved by compromises. Slavery was abolished in all states north of the Mason–Dixon line by 1804, but states in the south continued the institution, to support the kinds of large scale ag
