Timerover51
SOC-14 5K
So even back then, the Megacorps ruled!
I am not sure I would call them Megacorps back then, except for the Honourable East India Company, which did have its own navy as well as army. A fair number of those early companies did not succeed, and the backers lost their investment. In the case of Sir Walter Raleigh, his colonization and exploration efforts cost him his wealth, his son, and his life.
There are a fair number of company-owned worlds in the Traveller Universe, and if you are running your own Universe, a group of PCs setting out with a charter to take possession and ownership of any explored worlds would make for an interesting adventure. The Leviathan would be something close to that, but with a much smaller ship, striking out into a new area.