In March 2013 , he affirmed a commitment to completing the series with a fifth volume .
In November 2011 , Caro estimated that the fifth and final volume would require another two to three years to write .
In March 2013 , Caro affirmed a commitment to completing the series with a fifth volume .
In November 2011 , Caro estimated that the fifth and final volume would require another two to three years to write .