@MilHistNow: RT by @mikenov: Today in 1862, the Confederate invasion of Maryland is halted by the Union army at Antietam Creek near the town of Sharpsburg. Each side suffers an appalling 10,000 casualties in just 12 hours of savage fighting. It will be remembered as the bloodiest single day in U.S. history. pic.twitter.com/2CKNjtBM31