Well, it's a bit of a mix. While it may be inspired by some true elements from 1899 such as the general state of the world, sea travel, and social hierarchies at that time, it also has a lot of fictional elements added for the sake of drama and mystery. For example, the overarching mystery plot might be a creative take on some historical uncertainties, but not directly based on a single true story.
In many cases, 'True Story' is indeed drawn from actual happenings. The creators might take some artistic liberties, but the core elements are rooted in truth.
Yes, if it's labeled as a true story, it usually has some basis in real events. But there might be some creative liberties taken for entertainment or narrative purposes.
It depends on the specific work. Sometimes 'True Story' can be very closely tied to real events, while in other cases, it might just draw loose inspiration and not be a strict account of what actually occurred.