* He graduated from the United States Military Academy at West Point in 1826. Johnston was a distinguished student and was commissioned as a second lieutenant in the United States Army.
* He fought in the Black Hawk War and the Mexican-American War. Johnston served with distinction in both wars and was promoted to the rank of colonel.
* He was one of the first generals in the Confederate Army. Johnston was appointed as a general in the Confederate Army in 1861. He was one of the most experienced and respected generals in the Confederate Army.
* He was killed at the Battle of Shiloh on April 6, 1862. Johnston was killed by a Union sharpshooter during the first day of the Battle of Shiloh. His death was a major blow to the Confederate Army, and he was considered by many to be the Confederacy's best general.
* Johnston was a controversial figure during and after the Civil War. He was criticized by some for his handling of the Battle of Shiloh, and he was also criticized for his support of slavery. However, he is also remembered as a skilled general and a man of great character.