From 1766 to 1768, Rubí visited 23 (of 24) presidios scattered from the Gulf of California to present-day Louisiana, traveling overland about 7,600 miles (12,200 km) in 23 months.
His recommendations, later implemented, were that Spain withdraw from some presidios on its far northern frontier, including Louisiana and eastern Texas, and strengthen others which were in a poor state of readiness.
His father was Francisco Pignatelli y de Aymerich, a lieutenant general of the Kingdom of Aragon and ambassador to France.
King Carlos III of Spain began to focus on countering Britain and reforming and gaining control of its American colonies which it had neglected during the Seven Years' War that led up to the Treaty of Paris.
[7][8] Carlos made two appointments directed at getting better control and deceasing the costs of administering and defending New Spain (Mexico).
[9][10] Rubí arrived at Veracruz on 1 November 1764, as part of the expedition of Juan de Villalba, who was sent to New Spain to organize regular army and colonial militia units.
On August 7, 1765, King Charles III appointed Rubí inspector of frontier presidios and commissioned him to remedy economic abuses and other urgent matters.
When notified of his commission, Rubí went to Mexico City in mid-December 1765 and remained in the capital until March 1766, when he received his instructions from Viceroy Cruillas.
Turning eastward to Coahuila he noted a population there of 777 families of Spaniards, mestizos, and mulattos including soldiers at the three presidios.
From San Antonio, Rubí traveled eastward to Los Adaes in present day Louisiana and began his inspection there on September 14.
Subsequently, he also inspected the presidios at El Orcoquisac and La Bahía before leaving Texas at Laredo in November 1767.
He arrived in Santa Fe to find the settlers dependent on bows and arrows for defense, and the garrison at Los Adaes in Texas was not much better off, having just two muskets for 61 men.
North of this "real" frontier, which approximated the present international boundary between the United States and Mexico, Rubí advised that presidios be maintained only in San Antonio and Santa Fe.
Finally, Rubí recommended an offensive war to eliminate the threat of the Apache, including the capture of their women and children so they could not reproduce.