From which statement can we know the story is set in the past ?

There are actually a few statements that can answer this question.

"The log cabin in which she dwelt with her parents was just outside the enclosure in which she had been sleeping."

"There were ladies in the party. They walked awkwardly in their high-heeled boots over the rough, uneven ground, and held up their skirts mincingly. They twirled parasols over their shoulders..."