Jersey's Reform Day to be marked annually
Politicians agreed 28 September would celebrate the events of Reform Day, which took place on that date in 1769.
More than 100 people protested outside the Royal Court, which led to the separation of the powers of the States and Royal Court.
However, moves to put up a memorial and funding to be made available for research into the event were defeated.
Opponents of the propositions said there were other dates in Jersey of equal or greater importance.
Deputy Trevor Pitman, who led the move, also lost a motion calling for £3,000 to be made available to enable experts to reveal the texts of records from the time, which were erased on the orders of the Privy Council.
He said he would approach the Education, Sport and Culture Department in the future about getting the event included on the local history curriculum.