
Turns out that a

I first read about The Great Hedge, or The Customs Line, in the book Salt, by Mark Kurlansky (the guy who wrote the book Cod). So I went to the internet and there are literally no pictures of it and pretty much no information about it that isn't a review or summary of the book. Wikipedia has the most info you'll find.
So, two opressive regimes (The East India Company, and after the 1857 uprising, the British government) built a 2,000 foot long tree barrier in less than 50 years, and no one knows or cares. Imagine if the U.S. built a cholla, prickly pear, and mesquite fence across our entire Mexican border. Although it's not out of the question for Arizona to do that, I feel like it would get noted for its assholery and weirdness.
It seems like anyone who went to Calcutta during those 50-some-odd years would have at least heard about this monumental wall of shrubbery. I know I haven't read much that would possibly make mention of the Great Hedge (The Moonstone, Lord Jim?), but all signs point to no one writing about it. I guess my biggest question is: did contemporary authors know about this and choose not to use it for the sake of not making the British Empire look bad, or was it just not widely known?