Ernest Hemingway was a celebrated American author born in 1899 in Illinois. He served as an ambulance driver in World War I and was influenced by his experiences in his novel "A Farewell to Arms." Hemingway suffered from depression and bipolar disorder, which influenced his dark writing style. He wrote about his travels and lived parts of his life in Key West, Florida, where he took in many stray cats. Hemingway struggled with mental health issues and ultimately died by suicide in 1961.