"Cowboy Love Song", "Bright Sherman Valley", "Bright Laurel Valley", "In the Bright Mohawk Valley", and "Bright Little Valley"—depending on where it has been sung.Some think the song is of Canadian origin, dating from the time of the Wolseley Expedition (1870) which was a military force organized to put down the Red River Rebellion at the Red River colony in the Manitoba province. It was, according to Wiki, also intended to "counter American expansionist sentiments in northern border states."
Others think "Red River Valley" came from Iowa in 1879 because a manuscript of the lyrics exists which has a notation to that effect.
Wiki also notes that
The song appears in sheet music, titled "In the Bright Mohawk Valley", printed in New York in 1896 with James J. Kerrigan as the writer.There is no mystery, however, as to how popular the song is. It's one of the first songs many of us learn to sing. It's simple, hymn like melody is easy to follow and it's my opinion that the song embodies and conveys a wistful kind of natural spirituality and sentiment that even an atheist is comfortable with.
The lyrics suggest a hard truth--love, like life, is not eternal, does not last. The narrator seems to grasp this truth but resists it. He knows that his lover is leaving and asks for some sign of affection ("come and sit by my side if you love me"). He holds out hope against hope that somehow their love can be maintained, that it's not over.
There is also no longer a mystery as to which version of this song is the absolute, very best of all time. It's this one.