twitter.com/cspanhistory. in may of 2011, historian richard norton smith led a 10-day bus tour from asheville, north carolina to austin, texas, the group stopped at several presidential and historic sites along the route. one of the stops was the andrew johnson homestead in greenville, tennessee, a site owned and operated by the national park service. johnson served as vice president under president lincoln. and succeeded him when lincoln was assassinated. here's park guide daniel luther portraying president johnson and telling the story how andrew johnson met abraham lincoln. >> i...