When the General Council of the provisional government passed an act providing the council authority to elect two judges, Forbes was elected first judge of Nacogdoches Municipality on November 26, 1835. In December Gen. Sam Houston, John Cameron, and Forbes were appointed commissioners by provisional governor Henry Smith and the Consultation to secure a treaty with the Cherokees who were living near Nacogdoches. This treaty was signed by Chief Bowl, Sam Houston, and Forbes after a three-day conference with the Indians; the treaty bound the Cherokees to strict neutrality. Forbes also administered the oath of allegiance to army recruits, including David Crockett, as they passed through Nacogdoches. Forbes was then given the rank of major and appointed aide-de-camp to Sam Houston. He also served as commissary general under Houston during the campaigns at Anahuac and San Jacinto.
According to the accounts of Nicholas D. Labadie, Forbes murdered one or two Mexican women, took prisoners without justification, and reportedly took a gold snuffbox from the dead body of a Mexican colonel. After the defeat of the Mexican forces under Antonio López de Santa Anna, Forbes was placed in charge of the spoils of war and acquired Santa Anna's sword. Eventually his reputation was restored, after he filed a libel suit in a Nacogdoches court against Labadie, a suit that was on the civil agenda from 1859 to 1867. Forbes was cleared of all charges. He was discharged on November 17, 1836, from military duty. On his return to Nacogdoches, he served as principal judge of the Municipality of Nacogdoches, in which office he administered the oath of allegiance to many of the new Texans who arrived after the revolution. In 1856 he ran for mayor of Nacogdoches and won. He served in that capacity for several years. In 1876 he was appointed lieutenant colonel on the staff of Richard Coke. Forbes died on February 10, 1880, in Nacogdoches, and was survived by two daughters, who buried him beside his wife in the Oak Grove Cemetery.
31° 36.160, -094° 38.946
Oak Grove Cemetery