David L. Ulin at Literary Hub:
The letter rambled vividly and profanely through a crazy story about a few days in Denver in late 1945, beginning with Cassady meeting “a perfect beauty of such loveliness that I forgot everything else and immediately swore to forgo all my ordinary pursuits until I made her”: Joan Anderson. Its stream of consciousness is a rollercoaster ride through devotion, a breakup, a suicide attempt, a reunion, a reconciliation, an arrest, incarceration and, finally, abandonment. Appropriately, Cassady described the tale, mid-letter, as a “pricky tearjerker.”
This was what Kerouac admired most about the letter: the way Cassady’s personality exploded off the page. He had been looking for a strategy to open up his writing, and the immediacy of his friend’s account, full of digressions and moving back and forth in time, gave him an idea.