Historian Sean B. Palmer suggests that Carroll was inspired by a section from Shakespeare 's Hamlet , citing the lines : `` The graves stood tenantless , and the sheeted dead\/Did squeak and gibber in the Roman streets '' from Act I , Scene i. John Tenniel reluctantly agreed to illustrate the book in 1871 , and his illustrations are still the defining images of the poem .
John Tenniel reluctantly agreed to illustrate the book in 1871 , and his illustrations are still the defining images of the poem .