In the episode "Puffless", it is revealed that he died of lung cancer, which provoked Patty and Selma to abstain from smoking cigarettes. While Clancy does not appear with the rest of the Bouvier family in "I Married Marge", implying he was deceased before Homer and Marge were married, he is shown to be still alive when Bart and Lisa were toddlers in the episode "Walking Big & Tall", but he died before Maggie was born. Marge was particularly upset by her father's death, as Homer had to buy her a white noise machine to try and get her to deal with it.