The Articles of Confederation's only pro was to repel the dangers of a strong federal government. The incapacitating limitations in that regard were rectified by the U.S. Constitution, which maintained all the pros of the Articles of Confederation and eliminated its cons.
The Articles of Confederation were established to promote national unity, yet it failed in doing so by focusing more on the rights of states and individuals. The powers granted to Congress, such as making treaties and alliances, conducting foreign affairs and war, and regulating currency, in this first Constitution contained holes that made the nation impotent. Without the ability to regulate commerce, levy taxes and request money or troops from states, Congress could not make effectual decisions.
Following America's victory over Great Britain, the necessity of a more stable form of central government became more prominent. The Constitutional Convention set out to maintain the primary pro of the Articles of Confederation: protecting the rights of states and individuals. However, it also intended to introduce policies to ensure the country's capacity for growth, thereby removing the Articles' cons.
A system of checks and balances was applied to three branches of government, which alleviated the fear of excessive power within the central government. To guarantee accurate representation of the people, the Constitutional Convention settled on a bicameral legislature containing the House of Representatives (proportional representation) and the Senate (equal representation). Most importantly, the addition of amendments required approval from three-fourths of all states rather than the unfeasible consensus of all.