minibuffer-history-variable

minibuffer-history-variable is a variable defined in `C source code'.
Its value is

minibuffer-history

Documentation:
History list symbol to add minibuffer values to.
Each string of minibuffer input, as it appears on exit from the minibuffer,
is added with
(set minibuffer-history-variable
(cons STRING (symbol-value minibuffer-history-variable)))