Well, it started being developed between GTA 1 and 2, when GTA wasn't really Big and was barely starting out. GTA 3 was released like 3 years into development. Or Maybe the Wikipedia page lied to me and didn't actually start getting developed in 98.
Wow..... ima a huge Mafia fan. They made alot of changes compared to the final release..... too bad there were not much countryside (and missions there) in the final game....