Writing fictitious activity about historical figures

Writing about historical figures in a fictitous setting is ticklish. You have to be cautious not to upstage your own characters, you want to present the historical figures in some memorable way, and in the end you probably don't want to violate known history. You can write about a black child fathered by George Washington, because the historic setting certainly allowed for that. You can suggest that any Founding Father smoked opium - in Franklin's case it may well be true - so long as your story doesn't veer off and depict them opposite to known history.

In Where the gold is buried, I had to put the reader inside Fort Niagara in July, 1759. There is ample documentation on the French and British officers there, and a fair amount on the Haudenosaunee as well. When I decided to try 'solving' the mystery of the French military chest, I knew I had to learn what I could about Captain Pouchot. Among the first elements of his character clear from his writing was his affection for the natives. Given the widespread mingling between Europeans and natives, it isn't at all a hard stretch to presume Pouchot slept with Haudenosaunee women. Better than that, I decided to give him a wife. And because I grew up near the Tuscarora Reservation, and knew kids from the tribe, I decided to highlight them. So I created Sarah, the Tuscaroran woman who flirts with, seduces, then marries and bears a child to Pouchot. I'm pretty sure Pouchot did not marry in the European sense, but he may well have to the satisfaction of the tribe.