[1] Coppée served in the Mexican–American War as a lieutenant and was brevetted captain for gallantry at the battles of Contreras and Churubusco.

[2] During the American Civil War, he edited the United States Service Magazine.

[1] After resigning from the U.S. Army, he was the professor of English literature and history at the University of Pennsylvania in Philadelphia, from 1855 to 1866.

In 1866, Coppée was selected by Asa Packer to serve as the first president of Lehigh University in Bethlehem, Pennsylvania; he held this position for nine years, until 1875.

[5][6] During Coppée's tenure, the university underwent extensive development, including the construction of a number of new buildings and the expansion of the campus.