The following article was sourced from a Wikipedia page at the following address: http://en.wikipedia.org/wiki/Chesterfield_coat
The Chesterfield coat is a long, tailored overcoat. It arose along with the lounge suit as an alternative to the highly shaped coats it replaced, such as the frock overcoat with its heavy waist suppression using a waist seam. The Chesterfield has no horizontal seam or sidebodies, but can still be somewhat shaped using the side seams and darts. It can be single- or double-breasted, and has been popular in a wide variety of fabrics, typically heavier weight tweeds, or charcoal and navy, and even the camel hair classic. It has often been made with a velvet collar. These variations make it extremely versatile, so it can be worn with a city suit or even semi-formal dress, as well as casual sports jackets. It was a staple of smartly dressed men's wardrobes from the 1920s to 1960s, and is still very commonly worn.
It was named after the Earl of Chesterfield.
To read more about Chesterfield coats, please click on the following link: http://en.wikipedia.org/wiki/Chesterfield_coat