immediately vs whereupon

immediately

conj
  • directly (as soon as), instantly, the moment that. Indicates that the independent clause describes something that occurs immediately after the dependent clause's referent does. 

adv
  • In an immediate manner; instantly or without delay. 

whereupon

conj
  • After which, in consequence. 

  • Upon which. 

How often have the words immediately and whereupon occurred in a corpus of books? (source: Google Ngram Viewer )