'The Great American Eclipse' airs Monday, Aug. 21, at 1 p.m. ET on ABC

Watch the special live coverage of the first total solar eclipse that can be seen from the U.S. in 38 years. David Muir leads coverage from the 70-mile "path of totality" where the moon will block the sun entirely. Airs Monday, Aug. 21, from 1-3 p.m. ET.