The Union's Ulysses S. Grant opened a major offensive against the Confederates this week 150 years ago in the Civil War. It would be known as the start of the Overland Campaign, a bloody offensive that would yield staggering casualties frrom the first day as Grant's forces attacked a Confederate column early on May 5, 1864. The fierce fighting would rage for hours in dense woodlands, interrupted only by nightfall before the battle would rage again at dawn on May 6, 1864. In the end the battle by tens of thousands on both sides would prove a tactical draw. Still, Grant refused to retreat — marking the start of more fighting ahead in 1864 and the dawning of the bloodiest campaign in U.S. history.