The Grammy Award for Best Country Song has been awarded since 1965. The award is given to the songwriter of the song, not to the artist, except if the artist is also the songwriter.
There have been several minor changes to the name of the award:
From 1965 to 1968, it was known as "Best Country & Western Song"
From 1969 to 1983, it was awarded as "Best Country Song"
In 1984, it was awarded as "Best New Country Song "