His grandfather was Thomas Ferguson, a member of the General Assembly of South Carolina.

[1] Ferguson was a cadet with the South Carolina Military Academy (The Citadel), graduating in 1861.

He was a member of the gun battery on Morris Island that fired on the Star of the West during the Battle of Fort Sumter.

He served with the Confederate States Army as an engineer and directed the construction of batteries at Fort Sumter.

At the age of 25, he was promoted to major and commanded an artillery unit in South Carolina and was present at five battles.

[1] Ferguson was appointed by President Grover Cleveland as United States Ambassador to Sweden on February 14, 1894.