John Smedley, co-founder of the company*, thought to be the origin of the description Long Johns which he made (although some argue for the regular costume of boxer John Sullivan at the time).
http://2.bp.blogspot.com/_tkrYw-MBRN...a1f39b63_z.jpg
*near Matlock Derbyshire England - and claims to be the longest running factory manufacturing in the world as they produce designer knitwear to this day