What single event caused a re-evaluation of America’s first government?

The articles of Confederation.

Explanation:

The Articles created a loose confederation of sovereign states and a weak central government, leaving most of the power with the state governments. The need for a stronger Federal government soon became apparent and eventually led to the Constitutional Convention in 1787. Basically they passed these laws, but the laws were bad so they re-evaluated the government.

presidency should be the title