Why did the U.S. struggle after the American Revolution? Explain the economic, political, and social issues facing the young nation.

After the American Revolution, the U.S. was ruled under the short-lived Articles of Confederation. Ratified in 1781, the Articles lasted until 1789. The Articles of Confederation, as the name implies, set up a confederation of states that gave limited power to the federal government. As a result, the federal government could not regulate trade or issue currency. Different currencies complicated trade between states and with foreign countries, and the federal government also lacked the power to tax. As states did not always raise enough money through taxation or provide these funds to the federal government in a timely way, the federal government often faced budget shortfalls and struggled financially.
Politically, the leadership of the country was weak. Without a President, the country could not conduct foreign relations with any authority or deal with uprisings. While the Confederation had the power to declare war, it did not have the power to raise an army. Instead, the government relied on state militias. Shortly after the Revolution, the British Navy began to try to impress American sailors (meaning recruit or force them into their navy), but the federal government under the Articles lacked the power to respond effectively to these types of threats and to internal threats such as Shays' Rebellion in 1786-1787.
Socially, many people thought of themselves as Virginians, for example, rather than as Americans. There was a weak sense of belonging to a union that could tie together people from different states. The Constitution, ratified in 1788, began to create economic and political order and to create a deeper sense of national identity.