The main reason behind the colonists assembling for the first continental congress was to show their grievances towards the British government. The British government had very recently passed the Intolerable Acts and these Acts were vehemently protested by the colonists.The first Continental congress was held in the year 1774 between 5th September and October 26th. it was attended by the delegates of 12 colonies among the 13 colonies present during that time. This Continental Congress took place at Carpenter's Hill of Philadelphia. There were a total of 55 delegates present in this first Continental Congress.
