Final answer:
Jacob Riis' work 'How the Other Half Lives' exposed the living conditions of New York City's impoverished working class and led to significant social reform, including tenement laws and Progressive Era advocacy.
Step-by-step explanation:
The series of articles and the subsequent book 'How the Other Half Lives' by Jacob Riis significantly impacted social reform by exposing the harsh realities of life for factory workers and those living in poverty in New York City. Through his pioneering work in photojournalism, Riis depicted the deplorable conditions of tenements which many immigrant families called home. His work was instrumental in galvanizing public support for change, leading to legislation that aimed to improve tenement housing. These were some of the nation's first laws designed to improve living conditions for the impoverished working class.
In addition, Riis' work shone a spotlight on broader issues related to industrialization, such as child labor, worker's insurance, and safety in housing. The public outcry from the conditions he depicted contributed to a wave of Progressive Era reforms, including efforts to abolish child labor, improve worker welfare, and address urban squalor. Both the middle class and the working class became more involved in advocating for societal and institutional changes, ultimately influencing legislation and the improvement of workers' lives.