Why was the constitutional convention named the miracle at Phildelphia?

The Constitutional Convention and its accomplishments were considered a miracle because the of the sheer wealth of work, debate, disagreement, disenchantment, and distinct differences of the members and their visions for a new country. To think these men sat down, debated, proposed, and were able to write a document that provided a workable, agreed upon, and lasting Constitution, which formed a new and healthy republic, was indeed a miracle.