2. What was a key factor that made many impoverished people "invisible"
to society?

your list doesn't mention any of them at all.

and what does "these" mean anyway ?

hawaii was the final state

anyone who decides to disrespect or start absurd rumors without supporting evidence about congress or president will be charged/serve time and or fined @ jayxboof

i believe the answer is d. it was not uncommon for people to faint or even convulse at these high-energy meetings.