What was the original purpose of the constitutional convention, and what actually happened?

the purpose was to overthrow the king and establish a new government

the purpose was to edit or revise the articles of confederation, but instead they decided to start over and created an entirely new governmental system

they met to determine how to put down shay's rebellion and ended up electing george washington as king instead

The original purpose of the 'constitutional convention' was to edit the 'Articles of confederation' but they decided to recreate new 'governmental system'

Explanation:

The 'Constitutional convention' was the great consequence occurred in the United States Constitutional history. This was held in the year of 1787, May 14 to September 17 in 'Philadelphia', Pennsylvania. The delegates decided to create new government but officially, the convention had to be revise the existing 'Articles of confederation'.

From May 14 to July 14 the convention took series debate over fifteen points of the Virginia plan this was proposed by Madison to upgrade the 'Articles of confederation'. The 'committee of the Whole' didn't agree anything hence the 'Committee of Detail' was to handle the drafting process.  'constitutional convention' was adopted on 1787 September 17.