At some point, the presidential "campaign biography" gave way to the "campaign autobiography." 1920 fell between those two eras, with this contemporary article noting the demise of the former though the latter hadn't yet become the norm.
Changing Fashions in Presidential Campaigns
At some point, the presidential "campaign biography" gave way to the "campaign autobiography." 1920 fell between those two eras, with this contemporary article noting the demise of the former though the latter hadn't yet become the norm.