Child labor: The employment of children in factories and other industries during the Gilded Age, which was later regulated due to concerns about child welfare.
Knights of Labor: A prominent labor union that emerged during the late 19th century advocating for workers' rights and social reform.
Haymarket Riot: A violent incident that occurred during a labor protest in Chicago's Haymarket Square in 1886, leading to widespread anti-labor sentiment but also highlighting issues faced by workers.