You could make a pretty strong case that Neal Cassady was the single most influential force on 20th century counter-culture. The guy was a muse for Kerouac and Ginsburg and made the Beats what they were. Then, when that was all said and done he popped up on Ken Kesey's lawn in the mid-60s to drive Kesey's legendary school bus across the country and help ignite the Hippie movement.
But for a man who was such an important muse to so many writers, he never wrote much. His only real published work, The First Third, is fine, but it doesn't really live up to Kerouac's famous quote that Cassady was responsible for "the greatest piece of writing [he] ever saw."
That legendary piece of writing—a 40,000-word letter Cassady sent to Kerouac in 1950—is said to have inspired the electric, spontaneous style of On the Road. Up until a few years ago, it was believed to have been lost forever.
Dubbed the "Joan Anderson Letter" after a woman Cassady describes a love affair with, the fabled letter was rediscovered in 2012. On June 16, Christie's will be auctioning the hand-typed letter off, expecting it to go for as much as $600,000.
If you don't have a spare half a million sitting around, but still want to feast your eyes on the letter Kerouac said would "make Melville, Twain, Dreiser, [and] Wolfe ... spin in their graves," don't worry—Cassady's surviving family is planning to publish the whole thing sometime in the near future.