While historically, the speed at which information moved was slower than current times, firms still valued customer loyalty.

这个 While historically 并非一个整体，为便于理解，最好在 while 加上一个逗号：

While, historically, the speed at which information moved was slower than current times, firms still valued customer loyalty.

即 while the speed at which information moved was slower than current times 为让步状语从句。