Charles Jay Monroe was born November 20, 1839, in Lawrence, Van Buren County, Michigan to Jay Randolph and Fanny (Rawson) Monroe. During his childhood, he attended common school and worked on the family farm. From 1857 to 1860, Monroe attended Michigan Agricultural College (now Michigan State University). He took a law course at the University of Michigan in 1878-79.

In 1866, he moved to South Haven, Michigan, where he would remain until his death. He was employed in several fields, including surveying, teaching, banking, real estate, and farming. From 1860 to 1868, Monroe worked as a county surveyor. He worked in private banking in South Haven, from 1868 until 1871, when it was changed to a national bank. Monroe remained at the bank as a cashier and de facto manager. In 1879, he organized a bank in Bangor, Michigan, and served as its president. Monroe later became a director and president of Kalamazoo Savings Bank. Additionally, Monroe served as a school inspector, trustee of the Michigan Asylum (1890-1893), state Senator (Republican, 1883-1889), and member of the State Board of Agriculture (1894-1907), the governing body of Michigan Agricultural College (now Michigan State University).

On December 18, 1866, he married Hattie Morehouse (June 15, 1844 – August 22, 1903). Together they had four children, Stephen B., George C., Cora J., and Lucy E. Monroe was preceded in death by Hattie, and their two daughters. On September 16, 1905, he married Clara (Atkinson) Packard. Monroe died October 2, 1919, in South Haven.