The following units and commanders fought in the Battle of Palo Alto on May 8, 1846, during the Mexican–American War. 
 U.S. Army
 Zachary Taylor 
    | Unit type | 
  | Infantry |  | 
  | Mounted units |  | 
  | Artillery | Duncan's Battery (four 6-pounders)Ringgold's Battery (four 6-pounders)Heavy Battery (two 18-pounders)
 | 
 Mexican Army
 Mariano Arista 
    | Brigade | 
  | Lancer Brigade (Torrejon - 700 men total) | 7th Line Cavalry8th Line CavalryLight CavalryPresidial Irregular CompanyRanchero Irregular Company
 | 
  | Infantry | 2nd Light Infantry1st Line Infantry6th Line Infantry10th Line InfantryTampico Coastal Guard Battalion14 small cannon (4, 6, and 8-pounders)
 | 
 Sources
 - suite101.com/article/the-battle-of-palo-alto-may-8-1846-a310891 Military Suite 101 site