In the summer of 1910, Evangeline Simpson Whipple told the caretaker of her home not to move anything in her absence. The wealthy widow was going on a trip, but would be back soon, she said.

She never returned. When she died in 1930, she was buried at her request in Italy next to the love of her life — a woman with whom she had a relationship that spanned nearly 30 years. That woman, Rose Cleveland, had served as first lady.

The letters, preserved by the caretaker at Evangeline’s Minnesota home, are collected in a new book, “Precious and Adored: The Love Letters of Rose Cleveland and Evangeline Simpson Whipple, 1890-1918,” and make clear that they were more than just friends, according to its editors.

When Grover Cleveland took office in 1885, he was a nearly 50-year-old bachelor, a fact that almost derailed his campaign when rumors spread that he had fathered a child out of wedlock. (He had.) Protocol for unmarried or widowed presidents called for a female relative to fill the role of first lady. In stepped his sister, Rose.

She was seen as an important counterbalance to her brother’s scandalous baggage: She was respectable, well-educated, a former teacher at a women’s seminary and the author of serious books.

Her term as first lady, however, was a mixed bag, according to the National First Ladies’ Library. Her book of essays, “George Eliot’s Poetry,” became a bestseller based on her fame, but she was frustrated with public scrutiny of her necklines and a ban on her going to private dinners or public markets.