Complex sentence: Never having married, he revised his Last Will several times in an effort to assure his library was sustained after his death, until, on May 27,1846, he bequeath his library to the historical society in exchange for an annual salary of $600.
Split into simpler sentences: Never having married, he revised his Last Will several times in an effort to assure his library was sustained after his death. On May 27,1846, he bequeath his library to the historical society in exchange for an annual salary of $600.