In commemoration of Women’s History Month, Mystic Seaport is hosting a new exhibition in the R.J. Schaefer Building that uses photography to explore the lives of women in the 20th century. “On Land and Sea: A Century of Women in the Rosenfeld Collection” is a show containing 70 images based on a book of the same name by Margaret Anderson Rosenfeld. It illustrates lives of privilege and leisure as well as of working-class women from the turn of the last century through the 1950s. All of the pieces in the exhibit — “Etrolle” from 1916 is shown here — were taken by members of the Rosenfeld family of photographers, which included patriarch Morris Rosenfeld and sons David, Stanely and William. Seven themes are represented: Learning the Ropes; The Daily Grind — Women and Work; Lifelines — Women as Care Workers; Spirit, Sports and Spectators; Displaying Womanhood; In the Yard; and Women at the Wheel. The exhibition opens Saturday, and Margaret Anderson Rosenfeld will be on hand to sign copies of the book from 10 to 11 a.m. The show runs into September, with the exact date to be determined. Museum hours are 10. a.m.-4 p.m. Thurs.-Sun.; the exhibition is free with seaport admission, which is $28.95 adults, $25.95 seniors, $18.95 ages 4-14, and free for ages 3 and under; (860) 572-0711, mysticseaport.org.