John Forbes was born in Cork, Ireland in 1797. He immigrated to the United States around 1817 and settled first in Cincinnati, Ohio, where he married Emily Sophie Sisson. In 1834 they moved to Nacogdoches, Texas where Forbes became Chairman of the Committee of Vigilance and Public Safety. With Sam Houston he negotiated a treaty with the Cherokee Indians in 1835, and in 1836, as chief judge of Nacogdoches, Forbes administered Oaths of Allegiance to incoming Anglo-American settlers. During the Texas War of Independence, Forbes served as aide-de-camp to Houston, and was sent to Velasco to help Adjutant General John A. Wharton forward troops and supplies to the Texas Army. At the Battle of San Jacinto he was the Commissary General and drew criticism from disgruntled and hungry soldiers. Rumors grew up around camp about Forbes which later resurfaced in an article published in the 1859 Texas Almanac, by Nicholas Descomps Labadie, who served as a physician at the Battle of San Jacinto. Forbes sued Labadie for libel in a trial lasting from 1859 to 1866, at which time the suit ended in a draw with both parties ordered to pay their individual legal costs.