Bennet C. Riley was born on November 27, 1787 in St. Mary's County, Maryland. In the Catholic parish records of St. Mary's County preserved at Georgetown University is registered the marriage of one Bennet Reily to Susanna Drury on August 16, 1784. It is reasonable to suppose that these persons are Riley's parents especially since his widow signs her name "Riley" and "Reily" in the pension office records, but no other evidence has appeared to warrant a more definite statement.
He entered the military service of the United States on January 19, 1813, as an ensign of riflemen and at once saw active campaigning at Sacketts Harbor, New York, in the War of 1812, after which he accompanied his regiment to the Mississippi frontier.
From December 1816 to July 1817, he was adjutant of his regiment. On August 6, 1818, he was promoted to the rank of captain, having previously passed through the grades of third, second, and first lieutenant. Upon the disbandment of the rifle regiment in 1821, he was transferred to the infantry and for the next twenty-five years spent much of his time fighting Indians.
He was brevetted major in 1823 for distinguished service in a battle with the Arikara Indians in Dakota Territory.
In 1829 he convoyed a large merchant caravan from St. Louis, Missouri, to Santa Fé, New Mexico, and back again and received a sword from the legislature of Missouri in recognition of his services.
During 1831 and 1832 he fought in the Black Hawk War. He was promoted to the rank of major on September 26, 1837, and to lieutenant-colonel on December 1, 1839.
From 1839 to 1842 he participated in the Seminole wars in Florida, where his energy and courage won for him the brevet of colonel. At the beginning of the Mexican War he commanded the 2nd Infantry, but was quickly advanced to the command of a brigade. He participated in the siege of Vera Cruz and distinguished himself at Cerro Gordo where he was brevetted brigadier-general. It was at Contreras on August 20, 1847, however, that he won lasting fame. His brigade formed part of a force under Persifor Frazer Smith, which was sent around to the rear of the Mexican position, and Riley was designated to lead the assault.
In his official report of the battle General Smith says: "The opporunity afforded to Colonel Riley by his position was seized by that gallant veteran with all the skill and energy for which he is distinguished. The charge of his noble brigade down the slope, in full view of friend and foe, unchecked even for a moment, until he had planted all his colours upon their farthest works, was a spectacle that animated the army to the boldest deeds". For his gallant conduct on this occasion he was brevetted major-general.
He continued in command of his brigade to the end of the Mexican War. After the war he served in Louisiana and Missouri until the fall of 1848 when he was transferred with his regiment to California and assigned to the important command of the military department on the Pacific and became ex officio provisional governor of California.
In September 1849, he convened the constituent assembly at Monterey which drew up the first constitution for California and applied for admission into the Union. His able direction of affairs at this critical time greatly hastened the formation of the new state government to which he relinquished his authority in November 1849, when the first elected civil governor took office.
On January 31, 1850, he was promoted to colonel of the 16t Infantry and ordered to join that regiment on the Rio Grande River, but owing to disability from cancer he was unable to comply with the order. He settled in Buffalo, New York, where he died.
Riley ordered the election of representatives to a state constitutional convention, and handed over all civil authority to a Governor and elected delegates at the end of 1849; the following year, California joined the U. S. as a state. He participated in the War of 1812 on Lake Ontario. He also served in the United States Army during the Seminole War in Florida, and Mexican-American War.
He married Arbella Israel Riley on November 9, 1834. They had eight children.
