Pre-Columbian American metallurgy is consistently underestimated. Andean metalworkers achieved remarkable things with gold, silver, copper, and bronze. The absence of iron technology (which requires higher temperatures) was a technological constraint, not a sign of cultural backwardness.

The 7 Wonders science strategy being potentially unbalanced in multiplayer is the one thing I'd change about the design.

The Maya Long Count calendar, which tracks time from a creation date equivalent to 3114 BC, is one of the more impressive intellectual achievements in ancient American culture — a precise record-keeping system of remarkable temporal scope.

This is exactly the discussion I needed this week. Just got back from game night where Catan turned into a 3-hour standoff because nobody would trade with the leader.