What is the first book series written by R A Salvatore?

His first series was Forgotten Realms: Icewind Dale (1988-1990), which includes:

The Crystal Shard

Streams of Silver

The Halfling's Gem

Other early series he wrote are The Chronicles of Ynis Aielle (1990-2000) and Forgotten Realms: Dark Elf (1990-1991).