Probably never, except maybe during the period when only white male landowners could vote and so the "we" was a much smaller and wealthier group. Voter turnout is pretty high these days though.

https://www.electproject.org/national-1789-present

In the latter half of the 20th century, while many things were much worse than they are today, it was genuinely possible to support a family on a single minimum-wage job in many parts of the country.

Now, that doesn't mean that everyone used the extra time for civic participation, but when you compare that to today, when far too many people have to work two or three jobs per adult just to keep the lights on, I think it's fair to say that there was more free time.

I think the problem is more like:

When in American history have we had more things that are more engaging¹ competing with civic participation for our free time?

¹: and I think the terrifying answer might be:

    LOL, never, so? Hurry up and die.

Young people seem to have plenty of free time to march around the streets protesting, chanting and banging drums (which has pretty much zero effect on policy), but they aren't able to find the time to attend a city council meeting, or even vote, for that matter.

July 2020.

around May, 1886

and a lot more after