What were some events during the Confederation Period that were concerning to Americans?

Blockages, slavery, starvation.

Under the Articles of Confederation all 13 states had to approve any taxes and regulation of commerce. Attempts to revise the Articles went poorly, so those who wanted a 'United States' were left defeated. Some even wanted a return to a monarchy like the British had. Others thought only 3-4 different confederations would work. All of these would have left the new country weak and the victim of a strong enemy. Shays Rebellion showed the need for a stronger federal govt. to keep insurrections in check. This was likely the reason the country moved toward a stronger union. The beginnings of the USA were much more at risk than just the Revolutionary War itself.