hmm, I'm not really sure he was inspired by Hemingway in any meaningful way. Perhaps purely by coincidence is that true, with Hemingway winning the nobel prize a few years before this letter was mailed, and thompson actively copied heminway's work, as well as several other novels, in order to learn more about writing style, though he never published any plagiarized work.

Hemingway was a traditional, fiction, novelist and focused on his characters. Thompson defied (edit: was defined, oops) 100s of years of traditional writing (both novel and newspaper) by inventing so called 'gonzo' journalism. The man openly included his own personal life directly into all of this work, including this letter. He also, never worked in canada.

While I hold both men in high regard, the only parallels between these two men are the facts they both were journalists and authors (and drunks), since that's true for almost every published journalist, it's a thin comparison at best.