Do you mean 1776?
No, 1774. Much like picking a date when we entered Vietnam, you have to pick a year when the official government of this chunk of the North American contentinent -- now called The United States -- went too far and lost its just sovereignty. 1774 isn't a bad choice (though admittedly some more hotheaded than I would pick an earlier year).
we couldn't have won that war without a professional army, the French Navy, and French money to pay for it all.
They couldn't have won it without the American people.
And yet most of their successful attacks are IEDs.
Military technology is changed. As a weapon today the rifle is where the sword was in 1860-65. It's useful militarily in certain tactical situations, but basing your entire tyranny-prevention policy on rifles...
Let me finish that sentence for you, "...would be stupid." You use a handgun to fight your way back to your long gun. You use a long gun to harrass the enemy while you produce IEDs. As you note, the Taliban has fought us to a standstill with that approach.
The reason we keep the long guns around is so we can -- and this goes without saying, but god forbid it ever actually happens -- hold out long enough to get the rest of the operation live.
Their backup weapon is better then anything currently street-legal in the US (fully auto AKs are not street legal).
The arms in the hands of private citizens in the US are extremely effective -- far more so than the typical Russian surplus crap in Afghanistan. Automatic fire is rarely a practical use of ammo, and even three round burst is a minimally helpful luxury. If you wanted to, you could convert an AK-47 with simple hand tools and a few minutes effort. Automatic rifles are legal with an appropriate license, and you can shoot them at my local rifle range.