When O Henry began publishing his short stories few of reading audience knew they he was writing from prison?

That's a great question! It's true that O. Henry, whose real name was William Sydney Porter, was in prison when he began publishing his short stories. However, the audience generally didn't know about his incarceration.

Here's why:

* He used a pen name: O. Henry was a pseudonym, keeping his identity separate from his writing. This was partly due to his desire to escape his past, including his time in prison.

* His stories were popular: His humorous and witty short stories quickly gained popularity, with readers focusing on the stories themselves rather than the author's personal life.

* Prison was not widely publicized: While his conviction for embezzlement was public knowledge, the details of his prison life were not widely shared.

It wasn't until after his death in 1910 that the full extent of O. Henry's life story, including his time in prison, became widely known. This added a layer of intrigue to his already fascinating legacy.