Humans are the main races but non human races like the dwarfs and even elves are highly represented. Dwarves have multiple strongholds. And, the sword coast is littered with dwarf and elf stuff. In BG1, there was atcually a halfling village. Most major human cities including Baldur's Gate have sizeable non human populations. The fact that drow and tieflings are represented - espicially drow - says a lot.