Government under the Articles of confederation could not deal effectively with many issues that arose during the 1780's. Despite it's many weaknesses, the new government accomplished a great deal. The western lands became the prize and treasure of the new government. Since the Articles of Confederation could only request financial support form the states instead of demanding taxes, these western lands replaced taxes. The so called 'public domain'; or unsettled land were larger than all the established states put together. Therefore, by selling the land, the weak new government received money that it couldn't find in any other way. Instead of using this vast area like the European did with the thirteen colonies we made an 'Empire for Liberty.'; The Empire was built by adding new states. This was an extremely unique idea among people during the time. The charting of the vast western public domain was one way the government under the Articles of Confederation was praiseworthy. It was the greatest single achievement in domestic policy for the Confederation
Under the Articles of Confederation each state was given the power to regulate their own currency. Each state issued it's own money. As a result nobody knew exactly how much a New York dollar was worth compared to a one from New Jersey or Virginia. The more money there was in circulation, the less a dollar was worth. Finally, there was just a financial collapse and a paper money was considered worthless. For five long years the colonies experienced the worst business depression. This inefficiency to deal with the regulation of currency not only caused one of the worst depressions the colonists had ever seen but also set the groundwork for a major rebellion called Shay's Rebellion. People were so angry that their paper money had become worthless because of the initial problem of each state creating it's own currency, that a rebellion was organized by Daniel Shay to make banks and other money collectors accept cheap paper money. Men participating in Shay's Rebellion considered cheap paper money as bad as taxation without representation. As you can see government under the Articles of Confederation lacked the ability to effectively regulate currency because it caused a depression and a rebellion.
The U.S constitution attempted to solve the currency problem by making one standard currency for the entire country. This made it much easier to facilitate money between the different states. Now the states didn't have to transpose the value of for example New York dollar to a Virginia dollar. The standard currency throughout the country immediately solved many problems. The value of a dollar was raised and there was less money in circulation. It was a solution that cleared up many problems somewhat quickly.
Another major problem of the Articles of Confederation was the government had no President. When the people created the Articles of Confederation, they purposely did not want a President because they were afraid of giving any person too much power. This decision caused many problems such as lacking the power to raise and maintain a proper army and navy. Also other countries didn't respect us as much and therefore it was hard for us to negotiate treaties. This problem was obvious when Adams couldn't get the commercial treaty. This caused national security problems because we didn't have a President to act as Chief Diplomat, therefore other countries didn't respect us. From the period of 1781-89 there were Barbary pirates. Since the United States didn't have a navy, it could do little to protect the Barbary Pirate attacks in the Mediterranean Sea and Atlantic Treaty.
In order to solve this problem of national leadership, under the U.S. constitution the role of President was created. The President was made Commander-in-Chief of all the nation's armed forces. The President also had the power to negotiate treaties and appoint officials. This solution helped the country because one single person did not posses too much power but at the same time had enough power to make smart important decisions and run a country efficiently.
As you can see the Articles of Confederation had some successes and many failures. The U.S. Constitution attempted to resolve those failures, and in many cases it was successful.