Ira Mitchell DeLong was born in Monroe, Jasper County, Iowa to William and Susan Tool DeLong. He graduated from Simpson College (Indianola, Iowa) in 1878, as class valedictorian. In 1881 he received a master's degree in absentia from Simpson, based on his work in classics and mathematics. He began teaching mathematics in 1878 at Central Baptist College (Pella, Iowa), leaving that school in 1886 to become professor of Latin and principal of a prep school, Iowa Wesleyan College.
Ira DeLong's long ties with the University of Colorado began in the fall of 1888 when he became professor and head of the department of mathematics. From his arrival until his voluntary retirement as professor emeritus in 1925, DeLong was active as a teacher, an administrator, and C.U. representative at the biennial sessions of the state legislature. In the latter role, he sought to link C.U. with the rest of Colorado and to elicit fair appropriations and beneficial legislation.
Ira DeLong was influential in the business and cultural upgrading of Boulder, Colo. In 1890 he organized the Boulder Building & Loan Association, and in 1904 he helped to establish the Mercantile Bank and Trust Company. He served as an official and board member of both institutions, and helped to organize the Colorado Chautauqua Association and guide it through its difficult early years.
Ira DeLong was active in the establishment and operation of Boulder's city manager form of municipal government. He was president of a 23-member commission that drafted a city charter and constitution in 1917. Active in Boulder's civic and religious affairs, he served the Methodist Episcopal Church of Boulder and belonged to the Boulder Club, the Boulder Country Club and the Boulder Lions Club.
Dr. DeLong's professional affiliations included the Mathematical Association of America (he served as president of its Rocky Mountain Section), the American Mathematical Society ( charter member, 1891), the Colorado Mathematical Society (which he helped to found in 1905; he was its president from 1905 to 1907 and from 1912 to 1914), and the Colorado Education Association and the Colorado Schoolmasters Club, both of which he also served as president.
Ira DeLong was married twice: first, on 28 Aug. 1879, to Elizabeth A. Wright of Monroe, Iowa. Their two children were Edith E. DeLong Smith and Ruth DeLong Avery Henderson, both of Boulder. On 3 April 1929, he married Boulder socialite E. Vivian Sloan, widow, who died on 9 Oct. 1933. Ira DeLong died on 2 Sept. 1942 in Boulder, Colo. {Source: biog. sketch by Bruce Parham 1 July 1980, in his register of the DeLong papers; in archivist's collection file at Carnegie Library.}
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