[borgia]

>The armchair historian and anthropologist in me wishes we had something like this for the corporations of the 1800s.

What we do have from this time though are a huge number of private journals written/kept by very powerful and influential people. We also have huge troves of their mail correspondence that, without a doubt, was intended to be kept private.

We have since made these things public, written books about them, published the letters reprinted, etc.

So perhaps the release of such correspondence is merely a function of the time since its authorship, or the time since the author (and recipient?) died. The way things operate today though, the future historians are unlikely to get such content.