Sarah George Bagley (1806 -?) was born in Candia, New Hampshire and by 1837 she was working as a skilled weaver for the Hamilton Company in Lowell, Massachusetts. By 1840 she had moved to the dressing room (where she helped prepare warp threads for weaving) and with her earnings purchased a piece of land where her parents and siblings lived.
An outspoken critic of conditions for textile workers, Bagley was the founder and president of the Lowell Female Labor Reform Association (1845-47). She was also active in the New England Workingmen's Association and for a short time served as editor-in-chief of its weekly publication, the Voice of Industry. Well-known as a speaker, writer and organizer, Bagley circulated petitions to the Massachusetts legislature in 1846, demanding the 10-hour day and other reforms, but that effort did not succeed. Almost a decade later, factory operatives worked an 11-hour day in Lowell.
After leaving the mill around 1846 Bagley worked first as a dressmaker and then as a telegrapher. Apparently, she was also traveling around the state promoting labor and social reform and had become a member of the Lowell Union of Associationalists, a utopian socialist group. By 1847, however, she had faded from the reform scene and in 1848 she returned to the Hamilton Company as a weaver for at least a few months.