I did mapping as a college part-time job, mapping the state of Minnesota
Outfit was called the "Minnesota Land Management Information System."
There were multiple databases for the same areas, with categories like transportation, vegetation, population, geology, and whatever else they could think of. Thank God I had nothing to do with figuring out the parameters. I just plugged numbers and letters into little squares on a CRT. As I recall, the unit of area we used was the section (1 square mile).