Three different Mexican factions were known to have launched raids into Texas at the time but most of the evidence suggests that either Sediciosos or Carrancistas were responsible for the incursion.
By early 1915, a group of Mexican rebels, calling themselves Sediciosos, drafted the Plan of San Diego with the intention of bringing the American border states under the control of President Venustiano Carranza.
[4] However the superintendent of the Mexican National Railway, Esteban Fierros, was suspected of organizing raids during the summer of 1916 in accordance with the plan and even planned to invade the United States on June 10, the day American soldiers pursued a band of raiders to Matamoros and just five days before San Ygnacio was attacked.
[2] The Mexican Army, also known as Constitutionalistas or Carrancistas, which had already shown hostility towards the United States on several occasions and threatened to kill American soldiers.
This may not have been true though, according to Stout, because General Alfredo Ricaut, of the Constitutional Army, was campaigning against raiders during the time of the attack.
The Americans could not pursue any further because General Ricaut, under orders from Carranza, assembled 1,000 soldiers in Matamoros and threatened to attack them unless they returned to the United States.
Ricault also vowed to catch the raiders himself, armed the civilian population of Matamoros and "ripped up" the railroad tracks leading across the Rio Grande.
Carranza followed suit by concentrating his forces along the border and issuing a "general call to the civilians of Mexico to arm themselves" in preparation for an American invasion.
In addition, thousands of Americans living in Mexico began fleeing north, or to the safety of the United States Navy.
War would never come though, other than a raid near Fort Hancock, Texas on June 31, incursions into American territory ceased by July, which helped resolve some of the tension between the two nations.