Jenney was born in Fairhaven, Massachusetts on September 25, 1832 . His family celebrated a strong Puritan influence. His grandfather, Levi Jenney (1778-1849), was a shipping Captain . His father, William Proctor Jenney (1802-1881), was the owner of a shipping company, which allowed Jenney to travel as a young man . Jenney first began his formal education at the Lawrence Scientific school at Harvard in 1853, but transferred to L'École Centrale des Arts et Manufactures in Paris to get an education in engineering and architecture . He graduated in 1856, one year after his classmate, Gustave Eiffel, the designer of the Eiffel Tower. He later returned back to US to join the Union Army as an engineer in the Civil War in 1861, designing fortifications for Generals Sherman and Grant. By the end of the war, he had become a major, and was Engineer-in-Charge at Nashville's Union headquarters . After the war, in 1867, Jenney moved to Chicago, Illinois and began his own architectural office, which specialized in commercial buildings and urban planning.
During the late 1870s, he commuted weekly to Ann Arbor, Michigan to start and teach in the architecture program at the University of Michigan. In later years future leaders of the Chicago School like Louis Sullivan, Daniel Burnham, William Holabird, and Martin Roche, performed their architectural apprenticeships on Jenney's staff. On May 8, 1867, Jenney and Elizabeth "Lizzie" Hannah Cobb, from Cleveland, Ohio were married. They had two children named Max and Francis.
Jenney was elected an Associate of the American Institute of Architects in 1872, and became a Fellow in 1885. He served as first Vice President from 1898 to 1899 . He died in Los Angeles, California, on June 14, 1907 . After Jenney's death, his ashes were scattered over his wife's grave, just south of the Eternal Silence section of Uptown's Graceland Cemetery .
In 1998, Jenney was ranked number 89 in the book 1,000 Years, 1,000 People: Ranking the Men and Women Who Shaped the Millennium
Jenney is best known for designing the ten-story Home Insurance Building in Chicago. The building was the first fully metal-frame skyscraper, and is considered the first American skyscraper. It was built from 1884 to 1885, enlarged in 1891, and demolished in 1931 . In his designs, he used metal columns and beams, instead of stone and brick to support the building's upper levels. The steel needed to support the Home Insurance Building weighed only one-third as much as a ten-story building made of heavy masonry . Using this method, the weight of the building was reduced, thus allowing the possibility to construct even taller structures. Later, he solved the problem of fireproof construction for tall buildings by using masonry, iron, and terra cotta flooring and partitions . He displayed his system in the Second Leiter Building, also built in Chicago between the years 1889 and 1891.