Fr. Hennen was born and raised in Ottumwa, Iowa as the youngest of 11 children. He graduated with a B.A. in History and Philosophy from St. Ambrose University in Davenport, IA in 2000 and proceeded with studies in major seminary at the Pontifical North American College in Rome, Italy from 2000-2004.
He received his S.T.B. (Bachelor in Sacred Theology) from the Pontifical Gregorian University in Rome in 2003 and was ordained to the priesthood in 2004. He completed his S.T.L. (License in Sacred Theology), specializing in moral theology, from the Pontifical Lateran University in Rome in 2005.
Fr. Hennen served as Parochial Vicar at Jesus Christ Prince of Peace Parish in Clinton, Iowa from 2005-2010, and later as a Parochial Vicar at St. Mary's, Iowa City and Campus Minister at Newman Catholic Student Center, Iowa City. In 2011 he was named the Director of Vocations for the Diocese of Davenport . He is also a part-time senior religion teacher at Assumption High School.