What was the most pressing challenge facing The United States of America during the Articles of Confederation period?

The most pressing problems was the weakness of the Federal government to be able to do almost anything significant. King George is said to have complained that he didn't know whether "to send one ambassador or 13 ambassadors to the United States" because each state did exactly what they wanted. As a result, the government was almost bankrupt, the army was in disarray, and had there been a national crisis, there would have been no central government response because the central government had no real power. All the power rested with 13 bickering states. The leaders of the revolution, including George Washington, recognized that without a strong central government, the United States was doomed. So, Washington offered his home as a place for a Constitutional Convention and eventually a strong central government emerged from the chaos.