Which event convinced american leaders to call the grand convention?

The event that convinced American leaders to call the grand convention was Shay's Rebellion.

Shays’ Rebellion constituted a wave of violent attacks on courthouses and other government properties in Massachusetts, initiating in 1786, which resulted in a full-blown military confrontation in 1787.

The Grand Convention is the name given to the Constitutional Convention which took place from May 25 to September 17, 1787, in the old Pennsylvania State House in Philadelphia.

are these the benchmarks questions?

c) troops march forward in close formation against newer, more accurate weapons