A few months ago, Grant Moos was closing his boathouse, near Hackensack, Minnesota, as he does every summer, tying up loose ends, sweeping up debris. This year, though, his sister Kathy insisted that it was finally time to do something about six cardboard boxes that for decades had been stacked in a corner next to a 7.5-horsepower Evinrude engine.

The boxes belonged to their father, Malcolm Moos, a journalist and academic who was a speechwriter for President Dwight Eisenhower.