History support in query replace:

1. Query string
   • history: previous query-replacement pairs
   • future history:
     1. the word at point, if any
     2. the last successful isearch string
     3. previous query and replacement strings
2. Replacement string
   • history:
     1. the query string
     2. previous query and replacement strings
   • future history:
     1. the query string

(Search history with C-r and C-s, and navigate it with M-p and M-n.)