Why did delegates gather in 1787 for the constitutional convention?

The Constitutional Convention was held between May 14 and September 17, 1787 in Philadelphia, to resolve the problems of the United States government, which had been operating in accordance with the Articles of Confederation after its independence from Great Britain. Although the idea of the Convention was only to revise the Articles of Confederation, the intention of many of its proponents, mainly James Madison and Alexander Hamilton, was to create a new government instead of "fixing" the one that already existed. The delegates elected George Washington to preside over the convention. The result of the Convention was the Constitution of the United States of America.

they believed democracy was worth the fight