[1] He attended Don Bosco Preparatory High School in Ramsey, New Jersey and was a starter at offensive tackle as a junior and senior for the Ironmen.

[2] A 3-star offensive tackle recruit according to Rivals.com, Hennessy committed to play college football at Temple over offers from Air Force, Army, Florida Atlantic, Old Dominion, and Yale, among others.

[3][4] Hennessy played in three games with one start at left guard as a true freshman before redshirting the rest of the season.

[19] On September 24, 2024, with starting center Drew Dalman going to injured reserve, the Falcons signed Hennessy to their practice squad.

[22] On December 26, 2024, Hennessy signed a two-year deal with the San Francisco 49ers off the Falcons practice squad.