Henry B . Carrington Henry Beebee Carrington ( March 2 , 1824 – October 26 , 1912 ) was a lawyer , professor , prolific author , and an officer in the United States Army during the American Civil War and in the Old West during Red Cloud ' s War . A noted engineer , he constructed a series of forts to protect the Bozeman Trail , but suffered a major defeat at the hands of the warchief Red Cloud . Early life . Carrington was born in Wallingford , Connecticut . An ardent abolitionist in his youth , he was graduated from Yale University in 1845 . He was professor of natural science and Greek at the " Irving Institute " in Tarrytown , New York from 1846 to 1847 . Under the influence of the school ' s founder , Washington Irving , he subsequently wrote " Battles of the American Revolution " , which appeared in 1876 . In 1847 he studied at Yale Law School , taught school briefly at a women ' s institute , and the following year moved to Columbus , Ohio , where he practiced his profession in partnership with William Dennison , Jr . ( who was to become Governor of Ohio in 1860 ) . Carrington was an active anti - slavery Whig , and helped organize the Republican Party in 1854 . He became a close friend and supporter of Governor Salmon P . Chase and was appointed Judge Advocate General by Chase in 1857 , charged with reorganizing the state militia . Civil War service . Carrington subsequently became adjutant general for Ohio , mustering ten regiments of militia at the outbreak of the American Civil War and organizing the first twenty - six Ohio regiment s . He was commissioned the colonel of the 18th U . S . Infantry in May 1861 and established Camp Thomas near Columbus . In 1862 , Indiana Governor Oliver P . Morton requested Carrington ' s assistance to organize the state ' s levies for service . When he arrived in Indiana , a state of political warfare existed between Morton ’ s administration and its opponents . Morton had established an intelligence network to deal with rebel sympathizers , Knights of the Golden Circle ( Copperheads ) , Democrats , and anyone opposed to his rule , and Carrington was put at its head . In March 1863 , Carrington was promoted to brigadier general and made commander of the District of Indiana of the Department of the Ohio , later renamed the Northern Department . While Carrington succeeded in breaking up Morton ’ s enemies , his operatives carried out arbitrary arrests , suppressed freedom of speech and freedom of association , and generally maintained a repressive regime . His intelligence sources were recruited from disgruntled officials and unsolicited informers who gathered hearsay and unreliable information generally more valuable for political than military uses . } Carrington subsequently rejoined his old regiment in the Army of the Cumberland , and completed his war duty in the volunteer army in 1865 . Red Cloud ' s War . Following the Civil War , the 18th Infantry was stationed in the West . Carrington was then assigned as commander of the Mountain District , Department of the Missouri , in 1866 and moved his regimental headquarters to Colorado . Assigned to protect the Bozeman Trail , he built and personally manned the remote Fort Phil Kearny during Red Cloud ' s War . Carrington soon lost the respect of his officers due to his lack of aggressiveness in several Indian skirmishes . In December 1866 , a force of up to fifteen hundred Indians attacked a wood - cutting detail , then overwhelmed a reaction force of eighty troops under Captain William J . Fetterman . Fetterman , one of Carrington ' s antagonists , disobeyed his order not to pursue the Indians too far from the fort . Fetterman ’ s force was lured into an ambush and annihilated with no survivors . ( See Fetterman Fight ) Fetterman ’ s popularity , coupled with existing distrust of the colonel ' s leadership , led to rumors that his men had been ordered into the tragedy . General Ulysses S . Grant moved to court - martial Carrington but , at the suggestion of General William T . Sherman , submitted the matter to a court of inquiry , which subsequently exonerated Carrington , as did a separate investigation by the Department of the Interior . Nevertheless , Carrington had been relieved of command immediately after the disaster , so that his military career was effectively ruined . In 1868 , Margaret Carrington published her story about Fort Phil Kearny in a book titled " Absaraka , home of the Crows " . After Margaret ’ s death in 1870 , Carrington brought out new editions of the book with expanded details of his experiences ; the book eventually went through seven editions . In 1870 , Carrington retired from active service and was appointed professor of military science at Wabash College in Indiana , serving until 1878 when he moved to Hyde Park in Boston , Massachusetts . In 1871 , Carrington married Frances Grummond , the widow of Lt . George W . Grummond who was killed in the Fetterman massacre . He received the degree of LL . D . from Wabash College in 1873 . He briefly returned to the West and was instrumental in drafting a treaty with the Flathead Indians in Montana in 1889 . In 1890 , he conducted a detailed census of the Six Nations in New York and the Cherokee Nation . In 1908 , Carrington and his second wife , Frances C . Carrington , were honored in Sheridan , Wyoming , and Carrington spoke at the Fetterman massacre site memorial . With Carrington ' s help , Frances authored " Army Life on the Plains " in 1910 , detailing their experiences at Fort Phil Kearny .