There were poets long before Edgar Allen Poe.
But he saw the darkness and wrote about it.
He coined the phrase, "I gazed into the abyss and the abyss gazed back into me". He was historically mentally ill.
He ended up one of the greats. He wrote a story about a man talking to a bird. He wrote a story about the a man with a freaky eye and another man murdering that guy.
He was inspired by the darkness of the world and became known as mad.