Leon Ray Livingston was one of the most famous hoboes of all time, travelling under the name "A No.1". He perfected the hobo symbols system, which lets other homeless people know where there are more or less generous people, free food, vicious dogs, etc. He was not a poor man, he simply preferred a life of travelling the country by train to sitting at home. He has been lauded by many American historians as the King of the Hoboes, and has followings all over the USA.

Livingston wrote several books on travelling the hobo way, bringing attention not only to the state of the homeless in America, but also to the excitement and benefits of travelling the country for amusement.

During his later life, he continued to roam the country, but spoke out against youngsters following him. "I began out of neccessity, continued because I loved the life, and now because I know nothing else." He was buried under a grave marked "A No. 1 At rest at last"

His book From Coast to Coast with Jack London (ISBN 9-9903-4663-1) became the basis for the movie Emperor of the North, directed by Robert Aldrich, 1973.