After slavery was made unconstitutional. It only really came back into fashion during the civil rights movement. Do you need me to spell out the reason why?
Not the revolution itself but the period immediately after the Constitution was ratified. The intention of the Second Amendment was to avoid the cost of maintaining a permanent military establishment by creating a national guard of well ordered local militias. By 1812 we had more or less proved that wouldn't work.
The pinchpenny conservatives and their hatred of taxes is nothing new. Washington and his troops starved and froze at Valley Forge because the business lobby in the Continental Congress refused to vote on a tax bill that would have provided food and fuel. How anybody thinks we made America great without paying for it I don't understand.
After the War of 1812 when Britain was no longer a threat and we had our own army and navy to protect us, which meant a militia was no longer "necessary to the security of a free state."