After the colonists won the Revolutionary War, they formally received their independence with the Treaty of Paris, signed in 1783. This agreement recognized the United States as a free and independent nation. It also granted the new nation all of the lands east of the Mississippi River and north of Florida, which belonged to Spain. So this was truly a monumental moment in American history.
But the new nation faced many struggles immediately after independence, some of which stemmed from the government the states had implemented during wartime. Known as the Articles of Confederation, this loose association between the states was powerless to deal with many of the challenges the nation faced. It lacked the power to tax, the power to regulate interstate commerce, and the power to raise an army. Within the states, many struggled with the same issues of war debt that plagued the national government. Many thousands of Loyalists also left the new nation, in the largest refugee movement in American history. As states attempted to pass legislation that would pay off their debt through taxation, the ordinary farmers who inevitably suffered from these measures became angry, and, in Massachusetts, actually rose up in rebellion. The United States also faced the possibility of a Creek-led Indian war on its southwestern frontier, and one with Shawnees in the Ohio Valley. These issues would extend well into the 1790s.
In 1787, fearing that the national government was not powerful enough to address the nation's problems, and worrying in particular about the democratic governments that were being formed (or seemed likely to form) on the state level, a group of delegates from each state except Rhode Island met at Philadelphia to revise the Articles of Confederation. The government they created, the Constitution of the United States, was ratified by the requisite number of states in 1788, and went into effect, after a lengthy debate over its effects on states rights. When George Washington was sworn in as the new President in 1789, the nation entered a new chapter in its history.