As the title suggests, The Bughouse deals with Pound’s years in St. Elizabeths Hospital (which is now headquarters for Homeland Security; you can’t make these things up) after World War II.
Pound had made many treasonable statements in the late war, and there was much feeling that he should die for them, as the law suggested. (In France at that time, those who could claim participation in the Resistance were making life miserable for those who could not.) And yet there were those who felt that he was a great poet and, after all, his crimes had been mere speech, of a singularly inefficacious sort. In retrospect, putting him in the bughouse until people had calmed down seems an elegant solution. Swift discusses at length the question of whether he was “really” mentally ill, an issue I am enough of a Szaszian to consider tedious and unsolvable. (Thomas Szasz receives a single dutiful mention in the book.)
More interesting is the discussion of the work he created after he had gotten over the brutal treatment he had received in Italy, and how he functioned as a teacher to the many younger poets who visited him. (Robert Lowell dropped in many times, but they never tried to keep him.) If you are interested in Pound, this is a part of the story well worth reading.