Trouble in Triplicate

Nero Wolfe's character feels so distinctive and memorable. I wonder what inspired Stout to create such an eccentric detective with his particular habits and intellect.

The story seemed to focus heavily on the interactions and personalities of the characters. Was that a deliberate choice by Stout to deepen the mystery?

The city’s atmosphere added a lot to the story’s mood. I'm curious whether the setting was inspired by Stout’s own experiences or if it was chosen for its vibrancy.