The Nuttall Encyclopedia
A Welshman who, according to Welsh tradition, discovered America 300 years before Columbus, after staying in which for a time he returned, gave an account of what he had seen and experienced, and went back, but was never heard of more; his story has been amplified by Southey in an epic.
Wood, James, ed. Entry for 'Madoc'. The Nuttall Encyclopedia. https://www.studylight.org/encyclopedias/eng/nut/m/madoc.html. Frederick Warne & Co Ltd. London. 1900.