Sometimes historians don’t really know what to make of history, but that doesn’t stop them from trying. For example the assassination of John F. Kennedy is, though a case wrapped up by the Warren Commission, still debated. Historians use evidence, primary sources, and their own way of looking at things to deduct conclusions. Many people on the site of the assassination were interviewed some time after the incident. But if it weren’t for these somewhat vague accounts and sometimes misleading information given by the primary sources, drawing deductions, true or false, would be quite difficult. There would be a much more narrow range of history compared to the one we know today. So in the end, history is what people think happened based on historical evidence and sources that is available.