In the context of this excerpt from “civil disobedience” by henry thoreau, what does the word posterity mean?

this american government—what is it but a tradition, though a recent one, endeavoring to transmit itself unimpaired to posterity, but each instant losing some of its integrity? it has not the vitality and force of a single living man; for a single man can bend it to his will. it is a sort of wooden gun to the people themselves.

being remedied
a flawed government
future generations
a type of pest or vermin
a stubborn person