Given a passage and a question, find the answer to the question based on the passage. The answer should consist of only one word that lies in the span of only one of the sentences in the passage.
Q: Paragraph: In the history of the Triple Crown , 13 horses have won all three races : Sir Barton ( 1919 ) , Gallant Fox ( 1930 ) , Omaha ( 1935 ) , War Admiral ( 1937 ) , Whirlaway ( 1941 ) , Count Fleet ( 1943 ) , Assault ( 1946 ) , Citation ( 1948 ) , Secretariat ( 1973 ) , Seattle Slew ( 1977 ) , Affirmed ( 1978 ) , American Pharoah ( 2015 ) , and Justify ( 2018 ) . As of 2018 , American Pharoah and Justify are the only living Triple Crown winners .
Question: what was the last horse to win the triple crown

A:
Justify