"Sweet Dreams" or "Sweet Dreams (of You)" is a country ballad, which was written by Don Gibson. Gibson originally recorded the song in 1955; his version hit the top ten of Billboard's country chart, but was eclipsed by the success of a competing version by Faron Young. In 1960, after Gibson had established himself as a country music superstar, he released a new version as a single. This version also charted in the top ten on the country chart and also crossed over to the Billboard Hot 100, where it peaked at number ninety-three. The song has become a country standard, with other notable versions by Patsy Cline and Emmylou Harris.

In the summer of 1956 Faron Young recorded "Sweet Dreams" and took it all the way to #2 on the country charts. It was this version that garnered Gibson his first recognition as a talented songwriter.

In early 1963, Patsy Cline was recording songs for her next album, Faded Love, which was set for release in late March, 1963. However, on March 5, Cline died in a plane crash on the way home from a benefit in Kansas City, Missouri for the family of Cactus Jack Call, a disc jockey who was killed in an automobile accident so, therefore, the album was never released. The songs were later compiled for the release Patsy Cline the Last Sessions in 1988.

Instead, Decca Records issued a double album, entitled The Patsy Cline Story, in the summer of 1963.

In 1963, "Sweet Dreams" was released to the public and became a big Crossover hit, making it to #5 on the Country charts and to #44 on the pop music charts. It also peaked on the U.S. Adult Contemporary charts at #15. This song was followed by two other songs that were planned for release on Cline's upcoming album: "Leavin' on Your Mind" and "Faded Love", which both became hits.

...
Wikipedia