Am I understanding you to say that the worst, meaning most intrusive census ever issued to the public was that census from year 1900?
You would not believe all the nosy questions they asked (they didn't make it into the abstracts - you have to go look at the original handwritten ledger forms that were filled out by the census takers). Where parents born, parents occupations, wife the same, children. Was anyone chronically ill, feeble-minded, etc. Employment, employer, nature of work. Assets owned, real property, etc. etc. It filled up an entire sheet with a couple of families, just about.
It did vary, because some census takers were very punctilious about asking every single question -- others just let it slide. But it's a gold mine for genealogists. My gg grandfather on my mother's father's side was unfortunately quite elderly at the time, so it's apparent that one of his daughters answered for him. So I didn't get all the info I wanted!!