The M14 is kind of hard to place, because although it’s almost identical to an M1 and not an assault rifle it’s important despite being and deserves to be called out in that it introduced select fire in rifles.
So you have
M1 Battle Rifle : High Power, Self Loading, big, heavy
M14 Battle Rifle: High Power, Select Fire
M16 Assault Rifle: Intermediate Power, Select Fire
The museums at Springfield Armory and Rock Island Arsenal are well worth a visit if you’ve got an interest in US Martial arms history. They have M1903 and M1 serial number 1 & 2, a Pedersen device, etc. Overall I’m not impressed with US rifle design. The Krag, M1903, and M1917 were all copies of European designs. Probably the best of the bunch is the M1903A3. The problems with early M1903s literally blowing up in peoples faces were long gone (They had used a “that looks about right” method to determine when they had been properly heat treated, and the ones made on bright sunny days got heated too much, up to 300 degrees hotter) and it had an easier to use sight that was adjustable for windage like the M1s was.
I don’t disagree the M1 was a masterpiece, but it would have been even better and forward thinking with a lesser powered round, and there were problems with it that didn’t get ironed out until after the war such as the trouble with the site locking mechanism. With the M14 they kept the high power round, which made it even worse in practice as something that was heavy and difficult to control in semi-auto was even harder to control in full-auto. The M16 debuted before the bugs were out and had that huge problem with stuck cartridges.