Sarah Bagley (1806–1889) played a dual role as an inventor and a labor activist in 19th-century America. Integral to the rise of mechanized weaving in Lowell, Massachusetts, Bagley improved textile production, inadvertently affecting labor conditions. Her work highlighted the grim realities faced by workers amid industrial progress. Bagley emerged as a leading voice for labor rights, critiquing the harsh work environments created by technological advancements, and advocated for worker welfare during the Industrial Revolution.