Funnily enough, Allan Pinkerton spent little of his time as a detective, even though the term “private eye” is based on his logo. Most of what he did was espionage. With, you know, a little union-busting, as a treat. Still, he clinched the concept of a private detective outside the realm of the hired thug. Even though, yeah, Pinkerton agents are also hired thugs; just ask the person Wizards of the Coast sent Pinkertons after recently. But Allan Pinkerton did also thwart assassination plots against Lincoln before his inauguration, so that’s a net positive, at least?
In fact, the first fictional detective predates the public familiarity with Pinkerton. Charles Dickens created Mr. Nadgett in Martin Chuzzlewit, which I have not read on the grounds of hating Dickens and almost all of his works. Still, the golden era of pop culture fiction is the mid-twentieth century, definitely post-Pinkerton, and “private eye” is a phrase that gets used a lot. Whether it’s Sam Spade, James Rockford, or Kinsey Milhone, they’re all private eyes. And pop culture is full of them, of many varying types.
The first one to come to mind for most people is the hard-boiled. Your Sam Spade, your Philip Marlowe, your Mike Hammer. Tough men—they’re men—who drink a lot and are always on the verge of bankruptcy and generally have a secretary they sexually harass in some way. Probably there is a set of Venetian blinds in their office. They will almost certainly be shot at, if not actually shot, at least once in any given case. The bodies will just keep piling up.
At about the same time, we got a lot of Gentleman Detectives. (Also generally men.) Your Lord Peter Wimsey, your Hercule Poirot, your Nero Wolfe. Some of these were not officially set up as detectives and just kind of tripped into a lot of cases, but also there were some who had fancy apartments and were hired by expensive people. Nero Wolfe has a staff—enough so that he almost never leaves the brownstone. Though a lot of Gentleman Detectives were also globetrotters; how many countries did Hercule Poirot solve cases in?
Starting in about the ‘70s, you also got what is kind of the response to the two classic types. Jim Rockford, obviously—he’s hard-boiled, but in a more modern way. He’s got a bit of sensitivity. No secretary at all, because he can’t afford one, and he gets clients based on his ad in the phone book. It’s as though everyone realized there’s room for variety. You can have, say, a man in very short shorts who’s basically a rich man’s pool boy. You can have a man with crippling Obsessive-Compulsive Disorder. You can have the man who’s slipping into the life of a fictional character.
Who, in fact, was created by a woman in-universe, because that’s an extension of where detectives could go. Nancy Drew isn’t the first of the female detective characters, but she’s a good start. But as late as 1982, Laura Holt invented a male boss because no one wanted to hire a woman. (Which the first Enola Holmes book plays with, I discovered this week.) Yes, there’s Miss Marple, who’s kind of in the Gentleman Detective range—the Little Old Lady equivalent, along with Jessica Fletcher and others. Phryne Fisher, who predates the hard-boiled men on the timeline, inasmuch as she’s in the ‘20s, but who is a modern addition to the genre.
And, of course, there’s more than just white dudes. You’ve got Easy Rawlins, John Shaft, and Precious Ramotswe. And all of those are just in the English-speaking world; if you expand out of that, you’ve got dozens, if not hundreds. The private detective has a lot of choices. From Adrian Monk to Veronica Mars and beyond. You’ve got Harry Dresden, private detective/wizard. You’ve got Jessica Jones, private detective/superhero. Dirk Gently, private detective/whatever he needs to be on a given day. Fiction’s full of them, and they just keep going. Ask Benoit Blanc.