The article discusses several one-day battles with regard to the number of casualties as of April 2017, highlighting the Battle of Antietam in Maryland in September 1862 which was the bloodiest one-day battle in American history. These battles include the Somme Offensive on July 1, 1916, the War of the Roses at the Battle of Towton on March 29, 1461, and the battle in Borodino, Russia on September 7, 1812.