"The Rover Boys" was a very popular
series of
children's books written by
Edward Stratemeyer and the
Stratemeyer Syndicate. (Although many books put out by the syndicate were ghost-written, it's generally accepted that Stratmeyer wrote all these, the series he said was his favorite, himself.) The first book,
The Rover Boys At School, or, The Cadets Of Putnam Hall was published in
1899, and the last,
The Rover Boys Winning a Fortune, or, Strenuous Days Afloat And Ashore came out in
1926. The first 20 books deal with
brothers Dick, Tom, and Sam Rover, who are students at Putnam Hall for the first 12 books and go on to business and marriage eventually. The last 10 books in the series deal with the sons of the original Rover Boys.
The boys are from a rich family and often strike modern readers as obnoxious and snobbish, and the books also contain ethnic and race stereotypes that would never be published these days. However, they were very popular at the time and also spawned a spinoff series of 6 books set at Putnam Hall, the school the original Rover Boys attended, which did not contain the Rover Boys but did have other crossover characters. All of them follow a similar formula: "some humor, the cozy fun of school tales, far-flung adventures, dastardly (but basically harmless) nemeses and a
pervading undertone of clean living, patriotism, and healthy
boyish exuberance."
The A.Word.A.Day mailing list says that "rover boy" became a slang phrase to refer to a brave but naive person. Stratemeyer died in 1930, but the Rover Boys were also still well enough known in 1942 that the Warner Brothers cartoon studio released a parody, "The Dover Boys At Pimento University; or, The Rivals Of Roquefort Hall," directed by Chuck Jones and often referred to as the first cartoon to really show Jones' unique style.
Sources:
http://www.geocities.com/sbcentral/rover.html
http://www.larilana.com/stratemeyer/series/major/rover.htm
http://wordsmith.org/awad/archives/1103