I found this reference to a "Brussaen, Peter; Private; enrolled September 9, 1861 at Canton" whose name may well be yet another of the many garbled forms of the Brusseau surname I have encountered thus far.
Apparently he served from 9 September 1861 to 9 February 1863 in company A, 60th New York Infantry Regiment, Union Army. Discharged due to a disability.
Does anyone have any further information on this soldier or his family? I wonder if he is not the same as Peter Brusseau of Parishville, Saint Lawrence county, New York whose was born 12 March 1835 in New York State (source: 1901 census, Rossburn twp, Manitoba, Dominion of Canada). Certainly, his age at enlisted was 25 which was not far off his reported census age.