The knockout girl group song "Please Mr. Postman," by the Marvelettes was released on August 21, 1961. Later in the year it went on to become the first Motown single to hit #1 on Billboard's Hot 100 chart.
Motown wouldn't hit the #1 position again until 1963, when Little Stevie Wonder's "Fingertips, Pt. 2" reached the top. From that point on, Motown was a non-stop hit machine with at least one #1 hit on the charts each year through 1974. 1970 proved to be Motown's best year–they dominated Billboard with seven top hits.
The Marvelettes followed "Please Mr. Postman" with "Twistin' Postman," in an effort to cash in on their own song and the popularity of "The Twist." That song hit #34 on the pop charts, and was followed by their bigger hits "Playboy" and the current oldies radio staple "Beechwood 4-5789." Like a lot of groups of the era, the Marvelettes had a hard time cracking the charts once the British Invasion hit States.