Zack Steffen was in goal for the defending champions, with Reggie Cannon at right back, Matt Miazga and Aaron Long in central defense and Tim Ream at left back.
Michael Bradley was in the back of the midfield, with McKennie and Christian Pulisic ahead. Paul Arriola and Jordan Morris were on the flanks, and Jozy Altidore headed the attack.
McKennie scored in the 1-0 quarterfinal win over Curacao and had the first goal in the 3-1 semifinal victory over Jamaica.
Mexico coach Tata Martino made one change from the lineup that started the 1-0 extra-time win over Haiti in the semifinals, starting Uriel Antuna on a midfield flank over Roberto Alvarado.
Guillermo Ochoa was in goal, with Luis Rodríguez at right back, Carlos Salcedo and Edson Álvarez in central defense and Héctor Moreno at left back. Andrés Guardado, Jesús Gallardo, Jonathan dos Santos and Antuna were in midfield, with Rodolfo Pizarro and Raúl Jiménez up front.