In Boswell's Life of Johnson, James Boswell recounts how an acquaintance asked the eminent Samuel Johnson for a reference letter to help her son get into school. Johnson refused to do the lady the favor, writing her:
Madam, I hope you will believe that my delay in answering your letter could proceed only from my unwillingness to destroy any hope that you had formed. When you made your request to me, you should have considered, Madam, what you were asking. You ask me to solicit a great man, to whom I never spoke, for a young person whom I have never seen, upon a supposition which I had no means of knowing to be true... I have seen your son this morning; he seems a pretty youth, and will, perhaps, find some better friend than I can procure him...
Johnson wrote this letter in 1762, almost 250 years ago. Asking a connected acquaintance for a reference letter has always been a dicey business.