On the 112th anniversary of Ronald Reagan’s birth, we commemorate his many monumental accomplishments as the greatest president of the past century. But it is also a good occasion for correcting the record regarding the persistent, never-ending efforts to obscure those accomplishments with misleading smears. One attack on Reagan that has grown in the telling over the years is the claim that he invented a wartime story about having been present at the liberation of the Nazi death camps. The problem: The actual evidence of Reagan saying this is vague, thirdhand, and contradicted on the record by people who were...