^^^ my pleasure.
Just to add...from "The Ultimate Guide to Suits",
American (aka Sack Suit)
Historically an English cut dating to the Victorian era where it replaced the morning and frock coats. Originally a waistcoat, the sack's boxy, loose-fitting structure was often meant for outdoor activities like golfing, fishing, bicycling, etc. Also referred to as a lounge suit, the sack was considered casual wear until the late 1800's (1890 or so) when the sack became...