They were about the adventures of a trio of cowboys, many filmed at the Corriganville Movie Ranch, produced by George W. Weeks and distributed by Monogram Pictures.
The series used "Home on the Range" as its theme song with each film featuring the heroes waving goodbye and promising to return in another adventure.
When he and ventriloquist Max Terhune, who had made 21 films in the series, both had disputes over money with Republic, Corrigan went to producer George W. Weeks with the idea of a similar series that would be distributed by Monogram Pictures and filmed at the movie ranch with Western sets owned by Corrigan, the Corriganville Movie Ranch in the Simi Hills of the Simi Valley.
Monogram also had another "Trigger Trio" series of "the Rough Riders" which ended in 1942 after Buck Jones's death and Colonel Tim McCoy returned to active service.
Corrigan left the series temporarily over money disputes and was replaced by ace stuntman David Sharpe beginning with Texas to Bataan.