The earliest known year that women were at one time allowed to serve on a jury was in 1919 when an act was passed allowing many things including allowing them to serve on juries, become lawyers and judges. However, there is some controversy because this 1919 act did not always pertain to every woman in every state.
Different states allowed women to vote at different times. Some history shows that the last time women were finally allowed to vote in which everyone could vote would in 1975 which seems late. In the movie and book “To Kill a Mockingbird,” Miss Maudie would never have been allowed to serve on a jury along with any other woman in town because women were not allowed to vote.