The first thing is: you don't actually want historical accuracy. For example, you probably don't care how food is preserved or how people relieve themselves. You want historical verisimilitude.
I know this sounds like a quibble! But it makes your life so much easier. You don't need to be accurate. You just need to throw about a few interesting details.
And you don't need many details to add atmosphere. Usually, Wikipedia is all you need. Take a random example: let's say I want to write a scenario in medieval Paris. Now, I don't know anything about medieval Paris. But this Wikipedia article talks about the Black Death and Catholic-inspired violence. That's OK. That's all I need to give some colour.
And that means: yes, you can pick less "actiony" historical events. Your example of the Titanic is perfect. Set any scenario on board the Titanic and throw in a few historical details: a map, a menu, some details of etiquette. Use that as a backdrop to any scenario. Try a murder mystery, a horror story, a ghost story, anyway. All the historical detail fades into the background. It adds depth to the setting.
I hope this doesn't sound flippant. What I really mean is: don't worry too much about historical accuracy. It's important, in historical scenarios, that you play around with the history. Concentrate on the scenario, use the history as background/inspiration, and the game will work well.