Task: Question Generation
Input (English): Passage: More than 5,000 US troops of General John J. Pershing's forces, including elements of the 7th Cavalry and the African-American U.S. 10th Cavalry Regiment, entered Mexico in hot pursuit of Villa. The campaign consisted primarily of dozens of minor skirmishes with small bands of insurgents. Gen. Pershing failed to catch up to Villa. On 21 June 1916, two troops of the 10th, totaling 92 troopers, attacked Mexican Federal Army troops in an engagement in the Battle of Carrizal, Chihuahua. 12 US troops were killed and 23 taken prisoner; 45 Federales were casualties, including the Mexican general Gomez. The engagement nearly precipitated open war with the Mexican government , but both governments immediately moved to lessen tensions and open negotiations for US withdrawal, preventing war. The prisoners were repatriated at El Paso, Texas by the Carrancista government.
Output (English): What happened first: Battle of Carrizal or prisoners were repatriated?