Not too long after the release of Red Dead Redemption 2, news of a lawsuit filed by the still existing, real-life Pinkerton Consulting and Investigation company popped up.

Take-Two Interactive Software, parent company of developer Rockstar Games, filed a countersuit protecting its right to use the historically significant name in its work of fiction. Now, the situation has seemingly been resolved.
Pinkerton and its agents aren't depicted in the most positive light in Red Dead Redemption 2. Acting as the primary antagonists chasing the Van Der Linde gang, the agency is shown as a violent organization willing to employ extreme measures. Historically speaking, this is a fairly accurate depiction, but the company's modern incarnation which retains the Pinkerton name didn't take kindly to it - or the fact that it is possible to kill Pinkerton agents in-game.
We reported on the initial lawsuit back when it was filed, wherein Pinkerton sought to be paid royalties for the use of its name and historic logo in the game. It also sought damages over the alleged harm done to its reputation and public image due to the negative depiction.
The Pinkerton agency is a common element of Wild West fiction, be it literature, film or games, however the modern-day agency rarely files for royalties, if ever. This was used by Take-Two in their countersuit, and the publisher argued that the use of the Pinkerton name and logo in this historical context was fair use. Red Dead Redemption 2 strived for realism on many fronts, be it graphics, gameplay or historical accuracy.
Rockstar has used fictional stand-ins for existing companies, organizations or even cities in past games, most prominently in GTA, and even the settlements in Red Dead Redemption 2 are fictional - Saint Denis is a clear analog to New Orleans, for example. However, the Pinkerton agency wasn't altered in order to maintain realism, and due to their importance in the era the game depicts.
Take-Two has confirmed that the two parties have settles outside of court, with both the Pinkerton suit and the respondent countersuit have both been dropped. The legal document which notifies the court of Take-Two's voluntary dismissal is available online in full, though the same document from the Pinkerton side isn't (yet).
A Take-Two spokesperson gave a statement to The Verge, which was the first to report on the settlement.
Take-Two can confirm that the present-day Pinkerton Consulting and Investigation company has withdrawn its claims against Red Dead Redemption 2, and Take-Two will not continue legal action against Pinkerton. Red Dead Redemption 2 is a work of fiction set in the late 1800s that references historical entities active during that time.
No information about the settlement itself has been made public, so it is unclear whether Take-Two ended up paying Pinkerton. We certainly hope they weren't required to!