Ulysses S. Grant spent the last six weeks of his life in a hilltop cottage in upstate New York, a few miles from the Hudson River. The former president was broke, having lost all his wealth in a Ponzi scheme, and he knew he was dying—but he was determined to finish his memoir first, in the hopes that its royalties would be enough to support his wife Julia after his death. Grant had been invited to use this cottage as a writing retreat by William J. Arkell and Joseph D….