Unfortunately, but in my opinion, most of the best American music came out in the last century.
With that in mind, I will give you my $0.02.
Green Day "American Idiot"
The Black Keys "El Camino"
Eminem "The Marshall Mathers LP"
Johnny Cash "Hurt"
Tool "Aenima"
Tool "Fear Inoculum"
LP "Lost on You"
LP "Heart to Mouth"
Moby "Reprise"
As to "Bonus points for songs that cover the plight of generations or relevant sociopolitical situations at the time."
I may be off base, but most modern music seems to be just a copy of whatever they think will make them rich and famous.
Soulless, vapid and formulaic are words that come to mind.