Shays' Rebellion was never a real threat to the Massachusetts state government, but it alerted many observers to the shortcomings and fragility of the national government under the Articles of Confederation. Critics of the Confederation argued that the weak central government was vulnerable to "mobocracy" and could not sufficiently control its citizens or the individual states. The claim that the central government had only a weak hold on the states was furthered by rumors that the Spanish had offered exportation rights in New Orleans to western settlers if they would secede from the Union. With merchants and artisans calling for a strong central government to secure international trading rights, inhabitants of the frontier calling for a strong central government to combat the Native American resistance, and the signs of disorder and even secession prominent in their minds, delegates from each state traveled to Philadelphia to amend the Articles of Confederation. They did not know at that time just how much they would eventually change the framework of government.
The SparkNote on the Articles of Confederation contains a great deal more information on the text itself of the Articles, and on the specific historical circumstances out of which the Articles arose, and which proved the Articles' ultimate failure.