Daniel J. Vermilya is a Civil War historian who currently works as a park ranger at Gettysburg National Military Park. He has previously worked at Antietam National Battlefield in Maryland, where he is also a licensed battlefield guide. In 2012, he was awarded the first Joseph L. Harsh Memorial Scholar Award by the Save Historic Antietam Foundation. He is a native of Kirtland, Ohio, and has previously worked as a volunteer for the James A. Garfield National Historic Site.