Cooper enlisted as a sergeant in the 137th Illinois Volunteer Infantry, and was stationed in Memphis, Tennessee, during the Confederate raid on the city by troopers under the command of General Nathan Bedford Forrest. Following the war, he returned to complete his studies. Upon graduation from Knox College in 1867, he returned to his hometown of Greenville and was admitted to practice law in Illinois.
That same year, Cooper married Jane O. Barnes, the daughter of a prominent minister, and they had four children together. Leaving his family behind in 1872, he accompanied A. C. Phelps on a westward journey hoping to find entrepreneurial opportunities, and eventually settled in Denver, Colorado, where they started the law firm of Phelps and Cooper. In between 1872 and 1888, Cooper expanded his business interests to include insurance, banking, mining, and the cattle industry.
Cooper declined to seek reelection in 1890, and returned to his law practice. He later formed a construction business and built Denver's Cooper Building. From 1893 to 1897, he served as President of the local Chamber of Commerce. He died at the age of 55 and is buried in Denver's Fairmount Cemetery.
Family life
Cooper had a daughter, Mary Louisa Cooper, wife of geologist and railroad official, Lucius Seymour Storrs. The Storrs had two children, Lucius Seymour Storrs Jr., and Margaret Storrs Grierson.[2]
^Marquis, Albert Nelson (1915). Who's who in New England (Google Books Digitized June 4, 2007 ed.). Chicago: A.N. Marquis & Company. p. 1032. OCLC22884556.
