The group lead by Lewis and Clark was called the Company of Exploration.
Because Jack was his real name! I am not sure why though! His real name was Clive Staples Lewis, and from early childhood he preferred the nickname Jack. One story is that Jacksie was the name of a pet dog in the household that was hit by a car and killed, and Jack adopted his name and later shortened it to Jack.
Clive Staples Lewis changed his name to Jack because he preferred to be called by his childhood nickname, Jacksie. The nickname was derived from "Jacksie", a play on the surname Lewis. Lewis himself found the nickname more endearing and informal.
Corps of Discovery
Lewis Carroll's real name was Charles Lutwidge Dodgson. As he was a deacon at Christ Church College, Oxford University, he is given the title Reverend, so his name is often given as Rev. Charles Lutwidge Dodgson. He wrote books about mathematics using his real name.
The famous literary group was called the Inklings, and it included members such as J.R.R. Tolkien and C.S. Lewis. They met regularly at the University of Oxford to discuss and critique each other's work.
The White Stripes do have a female drummer, and her name is Meg White. She is the ex-wife of Jack White, the frontman and only other member of the group.
C.S. Lewis chose that name for himself when he was very young. The family dog was named Jacksie and when it was run over and killed, Lewis announced that he wanted to be called Jacksie. Later this was shortened to Jack.
doyen
shoshon
This occurred early in his life when the family dog was run over by a car and killed. Jack announced that he wanted to be called by the dog's name "Jacksie", which was shortened to Jack. IMHO it is much superior to "Clive", his real first name.
Clive Staples Lewis commonly referred to as C. S. Lewis and known to his family and friends as Jack (: