At President Abraham Lincoln's funeral in 1865, the oak tree stood just a few feet from the event, shading the funeral choir.
On the front lines of the controversy over hydraulic fracturing, the U.S. Environmental Protection Agency has, for the first time, confirmed what critics of the natural gas drilling practice have long suspected: fracking can contaminate drinking water supplies.
The news comes after the EPA conducted extensive testing of drinking water wells in central Wyoming where fracking, or injecting chemically-treated water into underground rock formations to push natural gas to the surface, has been widespread.
The EPA report is likely to put increased pressure on federal and state governments to move more quickly to regulate the industry.
Peter O’Dowd follows the route of Abraham Lincoln's funeral train 150 years ago, to look at modern-day race relations and Lincoln's legacy.