General Sheridan was only a Lieutenant General in 1881. He was promoted in 1888 shortly before his death.
This story is set in 1881 but in real life General Phil Sheridan was already married to his wife Irene since 1875. She remained married to him until his death.
The canoe would certainly have sunk without anyone bailing out the gallons of water being splashed in by the rapids.
Louis Riel married while in Montana in 1881 to a woman named Marguerite not Maria.
The actor playing Henri is Greek, not French Canadian.