Although it really cannot be done, there are those who attempt to find an era in some country in which libertarian ideas reigned. But there are valid attempts to show how certain eras qualify in one manner or another. Part of the problem is that conditions always change.
The United States, for example, has advanced liberty in some areas and degraded liberty in other areas. In the past there was much more economic liberty, but that was before slavery ended and before women and minorities were given the right to vote.
But generally it is assumed that the late nineteenth century in the western world, for all its flaws, had many of the characteristics of a libertarian society.
Many statists will immediately point to the flaws and say that it is the flaws that libertarians advocate. They are not interested in a true discussion or debate, only trying to find some ammunition, no matter how ludicrous, with which to try to tar libertarianism.
Then there's the temporal fallacy.
Due to advances in technology, there are amenities available today that were not available then. But there were advances then that were not available before then. True, compared to a modern factory, an earlier factory from the late 1800s would seem rather crude and dangerous – but it is better than what existed before then.
The fallacy is that everything that happened then is judged by today's standards. Thanks to advances in technology and worker productivity, companies can afford many more safety features than they were able to in the past. Those advances were not available then; therefore they were not implemented then. To the person committing the fallacy, that those advances were not implemented then is an unforgivable sin.
The fallacy is judging a factory from the 1880s by the standards of the 2010s. Of course it won't measure up. The factory must be judged in the proper context.
The factories of the day were, in general although there were exceptions, as safe as they could have been given the resources they had. People worked there because they were safer than other occupations and paid more than other occupations.
Yes, they didn't have closed circuit computer controlled safety systems. Of course those who commit this fallacy, when hard pressed, will admit that they don't expect closed circuit computer controlled safety systems, but then immediately turn around and deplore unmentioned safety protocols available today.
Conditions then were still an improvement over previous conditions. The economic liberty of the late 1800s created greater prosperity. And it is that same prosperity created then that enabled the more advanced technology available today - and the same prosperity that enables people to commit the temporal fallacy.