Hex & square drives were in use at the same time. There are an amazing variety. For example, the mid-1920s HUSKY ratchet from Milwaukee used a 5/8" hex drive. There are both square & hex drive versions of the "all malleable" Chicago Mfg. & Distributing Co. ratchet & socket sets based on the Gordon K. Wright March 10, 1914 patent no. 1,089,737.
Carl Bolt's museum in Oroville, CA has a whole board devoted to different socket drive sizes.