What brought about the need for social reform?

too many new immigrants
rapid growth of large cities
too little cultural diversity
industrial corruption

The Warlord Era (simplified Chinese: 军阀时代; traditional Chinese: 軍閥時代; pinyin: Jūnfá shídài, 1916–1928) was a period in the history of the Republic of China when control of the country was divided among former military cliques of the Beiyang Army and other regional factions, which were spread across the mainland regions ...