Clarence Edward Mulford was an early 20th century American western writer best-known for the Hopalong Cassidy character. Mulford wrote several dozen historically accurate novels with Hopalong as the central character. In Bar-20 Days Hopalong is a young man about to marry a neighbors daughter. Things get violent when a hot headed Mexican stirs up trouble between his outfit and the neighbors. Unlike the hero in film and television the Hopalong Cassidy of Mulfords books was a rude, rough talking cowboy. These stories are full of gun fights, range wars and western dialect.