 In February 1865 , Booth became infatuated with Lucy Lambert Hale , the daughter of U.S. Senator John P. Hale of New Hampshire , and they became secretly engaged when Booth received his mother 's blessing for their marriage plans . " You have so often been dead in love , " his mother counseled Booth in a letter , " be well assured she is really and truly devoted to you . " Booth composed a handwritten Valentine card for his fiancée on February 13 , expressing his " adoration " . She was unaware of Booth 's deep antipathy towards President Lincoln . 
