I've been to Cuba a couple of times now. The Cuban version of History, with respect to
events surrounding the American/Cuban embargo, Guantánamo Bay, Fidel Castro and
the many-many assassination attempts on his life, etc...sure has a different spin than
what one might learn in an American classroom, I'm assuming.
Same conflict, but different perspectives, with emphasis on different happenings, making
it sound like two very different versions of history.
That's why you have to avoid getting your history from one source, or perspective.
I have a perfect example.
In Ontario history classes, throughout all grades, Sainte Marie Amongst the Hurons, is the site at which the peaceful, hunter gathers of the Huron (Wendat), were viciously slaughtered by the aggressive savage Iroquois, for nothing more than lands and beaver pelts.
It doesn't matter that, there was rampant disease wherever the Blackrobes went. This of course would be a bad sign to a group of people who were unfamiliar with these diseases.
It doesn't matter that these peaceful hunter gatherers, were among the first to scalp enemies for cash from the French.
What matters is, the Blackrobes Brebeuf, Chabanel, Lalande, Garnier, Goupil, Lallemant, were martyred, Canonized and the place is now a shrine to mangled history and the assault on Native culture.
They must be, somewhere, or you wouldn't know about them. And that's the major point about historical scholarship. History is a developing story much like science is, it changes as new evidence comes to light, new tools are developed, new insights appear, new personalities with different interests join the field, and so on. And just like science, it'll never be complete, but it has similar methods of self-correction, and to that degree can legitimately be called a science itself. So to answer the question posed in the thread title, history is as factual as historians can make it and they're constantly working to improve it.
The problem lies, in the fact that people don't know how to identify a real history, from a hack with an agenda.