Born Susan Dean, she was orphaned at the age of four and adopted by the Langdon family. Though Susan was nearly ten years older than her foster-sister, Olivia Langdon Clemens, they remained close throughout their lives. In 1858 she married Theodore Crane, who would later become a partner in the Langdon family coal business. Susan Crane owned Quarry Farm, in Elmira, New York, where the Clemens family usually spent the summer, and where Samuel did much of his most famous writing in a small building specially made for him. Samuel also convinced her to be an investor in both the Paige typesetting machine and in his Charles L. Webster Publishing Company.

Theodore Crane, after marrying Susan, went into business with his father-in-law, Jervis Langdon. “Theodore Crane was competent in his line – that of head clerk and Superintendent of the subordinate clerks,” wrote Clemens. He described Crane’s absolute reliance on Susan Crane: “He will die if he has to go ten days without seeing Sue.”

“Aunt Sue was the one person I have ever seen who appeared to be continually above and beyond the hurts inflicted by human existence,” Clara Clemens wrote. “Father sometimes called her Saint Sue, and she returned the compliment by calling him Holy Samuel, though with a strong touch of humor in her tone of voice.” Samuel Clemens himself wrote in late life: “Her head is white now, but she is as pretty and winning and sweet as she was in those ancient times at her Quarry Farm, where she was an idol and the rest of us were her worshippers.”