Complex sentence: In Harding's youth, the majority of the population still lived on farms and in small towns, but the rural population, though still increasing, was not rising as quickly as the urban, and the latter would become more numerous around 1906.
Split into simpler sentences: In Harding's youth, the majority of the population still lived on farms and in small towns. That rural population, though still increasing, was not rising as quickly as the urban, and the latter would become more numerous around 1906.