"Silverstein narrowly avoided the world's first cartoon-related court martial over a comic strip that seemed to imply officers were dressing their families in stolen uniforms."
There's a piece on Shel Silverstein up at mental_floss.
The whole thing's worth reading, but I especially got a kick out of this bit about The Giving Tree:
Those who branded Silverstein's work as unfit for children were certainly extremists, but that's not to say Uncle Shelby didn't have a dark side that could be a bit unnerving at times. There are hints of this even in The Giving Tree, which tells the story of a generous tree that repeatedly donates parts of itself to a needy boy until it's nothing more than a stump. Although the book is considered a classic today, after Silverstein finished it in 1960, it took him four years before he found anyone willing to publish it. Apparently, editors found it too depressing for kids and too simple for adults. It wasn't until his other titles started raking in the dough that Harper & Row was confident enough to give it a shot.