The Articles of Confederation, which was the United States' first constitution, failed because it did not give the national government sufficient power to effectively govern the country. Under the Articles, the national government was weak and had limited powers, while the state governments were powerful and held most of the authority. This led to many problems, including the inability of the national government to levy taxes, regulate trade, or maintain a standing army. In addition, the Articles did not provide for a national court system or a strong executive branch, which made it difficult to enforce laws and policies.
The United States Constitution, which was adopted in 1787, improved upon the Articles of Confederation in several ways. First, it created a stronger national government with more powers, including the ability to levy taxes, regulate trade, and maintain a standing army. Second, it established a clear separation of powers between the three branches of government (legislative, executive, and judicial) and provided checks and balances to prevent any one branch from becoming too powerful. Third, it established a federal court system and a national system of laws, which helped to ensure that the laws were applied consistently throughout the country. Finally, the Constitution provided for a more effective method of amending the document, which made it easier to adapt to changing circumstances and needs. Overall, the Constitution addressed many of the weaknesses of the Articles of Confederation and provided a more effective framework for governing the United States.