Pierre Gustave Toutant-Beauregard (May 28, 1818 – February 20, 1893) was an American military officer known for being the Confederate general who started the American Civil War at the battle of Fort Sumter on April 12, 1861. Today, he is commonly referred to as P. G. T. Beauregard, but he rarely used his first name as an adult. He signed correspondence as G. T. Beauregard.
Trained in military and civil engineering at the United States Military Academy, West Point, Beauregard served with distinction as an engineer officer in the Mexican–American War. Following a brief appointment as superintendent of the U.S. Military Academy in 1861, and after Louisiana seceded, he resigned from the United States Army and became the first brigadier general in the Confederate States Army.