The Hartford Convention was an expression of the dissatisfaction of New England states. They did not support the 1812 war with Britain, they were afraid of a land invasion. For the first time, representatives of some states discussed separation from the Union. The convention demanded the approval of a reform that would require two thirds of the Senate to declare war, but a guarantee of no future wars with Britain wasn´t discussed specifically.
The allied invasion of D-Day was when aircraft, ships, and thousands of British, American, and Canadian troops came on the shores of France to restore Europe from WW2.
