Robert Barclay Allardice of Ury, Kincardineshire took any bet when it came to walking.
In 1809, he walked 1000 miles in 1000 hours for 1000 guineas. He stood to lose roughly £100,000 if he failed. Overall ~£5million was wagered on his race.
Field. Saturday 27th May 1854. pg. 9
Thom, W. (1813) Pedestrianism; or, An account of the performances of celebrated pedestrians during the last and present century : with a full narrative of Captain Barclay’s public and private matches; and an essay on training. D. Chalmers and Co., Aberdeen. 286pp