[1] In 1854, Governor Hoppin helped spread rumor of an armed Catholic conspiracy in Rhode Island.

[1] In response to this imagined threat, Hoppin provided uniforms and weapons to form the "Guards of Liberty," a military unit whose members consisted solely of native-born white Protestants.

When the war began he was a staunch supporter of the Union cause, campaigning for Abraham Lincoln in 1860 and 1864, and Ulysses S. Grant in 1868 and 1872.

He was a hereditary member of the Rhode Island Society of the Cincinnati and served as its vice president.

He was also a 3rd Class Companion (i.e. honorary member) of the Massachusetts Commandery of the Military Order of the Loyal Legion of the United States in recognition of his support for the Union during the Civil War.