captain david derickson of the 150th pennsylvania infantry was lincoln's bodyguard and companion between september 1862 and april 1863. they shared a bed during the absences of lincoln's wife, until derickson was promoted in 1863. derickson was twice married and fathered ten children. tripp recounts that, whatever the level of intimacy of the relationship, it was the subject of gossip. elizabeth woodbury fox, the wife of lincoln's naval aide, wrote in her diary for november 16, 1862, "tish says, 'oh, there is a bucktail soldier here devoted to the president, drives with him, and when mrs. l. is not home, sleeps with him.' what stuff!" this sleeping arrangement was also noted by a fellow officer in derickson's regiment, thomas chamberlin, in the book "history of the one hundred and fiftieth regiment pennsylvania volunteers, second regiment, bucktail brigade". historian martin p. johnson notes that the strong similarity in style and content of the fox and chamberlin accounts suggests that, rather than being two independent accounts of the same events as tripp claims, both were based on the same report from a single source. david donald and johnson both dispute tripp's interpretation of fox's comment, saying that the exclamation of "what stuff!" was, in that day, an exclamation over the absurdity of the suggestion rather than the gossip value of it (as in the phrase "stuff and nonsense").