It was the period of my mental progress which I have now reached that I formed the friendship which has been the honour and chief blessing of my existence, as well as the source of a great part of all that I have attempted to do, or hope to effect hereafter, for human improvement. My first introduction to the lady who, after a friendship of twenty years, consented to become my wife, was in 1830, when I was in my twenty-fifth and she in her twenty-third year.

Autobiography (1873)