The Mangle. Sage Adair Historical Mysteries, #6

In this sixth book of the series, Sage's mother Mae goes undercover as a steam laundry worker alongside women working six-day weeks, ten-hour days. Exhausted and ill the women implore the laundry owners to institute nine-hour workdays. The insertion of white slavers, arsonists, and kidnappers into the ensuing labor dispute leaves Sage facing a nearly insurmountable problem when two women disappear.
Even as Sage, Mae, and their colorful associates hunt for the missing women, they continue their effort to help the laundry workers win relief. Like the series' previous books, The Mangle is a story built around the true-life actions of ordinary people at the beginning of the twentieth century. This time the focus is on the progressive women who were tackling a number of social injustices: wage inequality, prostitution, social diseases, and poverty. As the historical notes at story's end reveal, these women's efforts changed history-for the entire country.
Their case went before the Supreme Court, creating new legal precedence, paving the way for their attorney to eventually becoming one of the country's most revered Supreme Court Justices, as well as being written about by another great Justice, Ruth Bader Ginsburg.