[4] He served in 13 engagements during the war including Second Bull Run, Chancellorsville, Fredericksburg, Gettysburg, the Wilderness and Spotsylvania Court House.

[3] Cooper served as a delegate to the 1860 Republican National Convention in Chicago, Illinois and had a pivotal role in the nomination of Abraham Lincoln.

In 1889, Cooper was appointed by President Benjamin Harrison as collector of the Port of Philadelphia, and in 1900, he was elected again to the Pennsylvania House of Representatives for Delaware County and served until his death in 1909.

[3] Cooper was a member of the George W. Bartram Lodge, Free and Accepted Masons and of the Bradbury Post, Grand Army of the Republic.

[3] Cooper died in his home in a fire started by his own cigar[5] and was interred at Media Cemetery in Upper Providence Township, Delaware County, Pennsylvania.