He played a significant role in Apache warfare until the mid-1860s, along with his contemporaries Cochise (who would go on to be the principal chief of the Tsokanende or Chiricahua) and Nana, as well as younger leaders such as Victorio, Loco, Juh, Chihuahua, and Geronimo.
He may not have been the real leader of all the Mimbreños, however, since in the meantime younger Victorio, Mangas Coloradas's son-in-law, achieved even higher fame and prestige because of his extraordinary abilities as a warrior and a warlord, succeeding Cuchillo Negro as chief of the "Warm Springs" Mimbreños to every extent (so going elderly Nana to be a precious and worthy lieutenant and long-time allied of the same Victorio).
After parleys in the spring of 1850, Delgadito and some other Mimbreño and Nednhi chiefs signed a treaty that summer in Janos with Chihuahua representatives.
In June 1851, Delgadito, Ponce and Coleto Amarillo accompanied Mangas Coloradas to Santa Rita del Cobre to meet John R. Bartlett, the U.S. commissioner appointed by Washington to the United States and Mexican Boundary Commission, until the Apaches did not feel disappointed and betrayed by the Anglo-American newcomers.
In spite of the good will of the chiefs (Mangas Coloradas, Cuchillo Negro, Delgadito, Ponce and Coleto Amarillo), who had to intervene repeatedly to prevent any drastic reaction by the warriors, relations became more and more difficult until the Apaches broke them.