It all started with Civ 1. Out of nostalgia and as a natural companion to our Civ 6 advanced Civilopedia search, we built one for the original game as well.
Since Civ 1 is much simpler in scope we were able to catalog the entire game completely, making this a fully searchable reference for everything in it. Every unit, technology, city improvement, and wonder is fully tagged and filterable.
Give it a shot, it's where it all started.