In Glaspell's short story "A Jury of Her Peers," the main conflict pits the men's arrogant air of superiority and seemingly logical methods against the women's responses to the conditions of Minnie Foster's life. Therefore, it would seem that the protagonists are the women and the antagonists the men.
As the sheriff, the county attorney, and the neighbor Mr. Hale go upstairs to the site of the murder where they search for clues, the sheriff's wife and Mrs. Hale remain in the kitchen, an area where, as the sheriff remarks, there are "[N]othing...but kitchen things." He deems the area not worth investigation. However, this logic proves to be wrong since the accused murderer, Mrs. Wright, spent much of her time in this kitchen.
While Mrs. Peters hangs up her coat, she notices a sewing basket and a quilt on which Mrs. Wright was working. The sewing, which has been very neat is, for some reason, quite erratic on one section."Why, it looks as if she didn't know what she was about!" Mrs. Peters exclaims. Mrs. Hale pulls out the bad stitches and makes them right. "What do you suppose she was so--nervous about?" Mrs. Peters asks her.
Having noticed a birdcage, Mrs. Peters then inquires if Mrs. Wright has owned a bird. Mrs. Hale tells her there was a man selling them who "came around" one time. "I should think she would've wanted a bird!" Mrs. Hale adds after recalling what a "hard man" Mr. Wright was. As a second thought, she suggests that Mrs. Peters take the quilt and some sewing materials to the jail for Mrs. Wright.
When Mrs. Peters looks for some paper and string to wrap the items, she discovers a pretty box that may have scraps for quilts in it. Instead, she finds a dead bird wrapped in a piece of silk. The two women stare at it pointedly. Mrs. Peters whispers, "Somebody wrung its neck." But, hearing a sound at the door, Mrs. Hale quickly hides the box under the quilt in the basket.
After Mr. Hale goes out to the horses and the sheriff and county attorney move to the other room, Mrs. Hale exclaims,
"Oh, I wish I'd come over here once in a while! ... That was a crime! Who's going to punish that?"
At the approach of the men, they hear the county attorney say,
"If there was some definite thing.... A thing that would connect up with this clumsy way of doing it!"
Mrs. Hale quickly grabs the box from under the sewing, and she shoves it into her coat pocket. The two women "held each other in a steady, burning look" of empathy.
Mrs. Wright has been found not guilty by "the jury of her peers." The protagonists have solved the problem and probably saved Mrs. Wright's life.
There are two interpretations that respond to your question. In one reading, the absent, imprisoned Mrs. Minnie Foster is the protagonist for the meaning and action revolve principally around her: it is her story that her neighbors, Mrs. Peters and Mrs. Hale tell. She functions beyond herself as a character; she represents the women who figure out her story, because in many ways her life is theirs—which is why they understand it. The antagonist would be her dead husband, for it is he and all the forces of society—a patriarchal power structure—that he represents that repressed her to such a degree that she murdered him. It could also be argued, however, that Mrs. Hale and Mrs. Peters are the protagonists, heroically protecting Mrs. Foster by figuring out the details of the murder. Their husbands would then be the antagonists because they function in direct opposition to them. Although these men appear so inept in their actions and ideas that they are little match for the women. in the story, they nevertheless represent a power structure against which the women must contend.