Robinson B. Murphy was born on May 11, 1849 in Oswego, Illinois. Murphy attempted to persuade a regiment leaving from Joliet to take him along in 1861. He was found out and returned home befor the regiment left for battle. In 1862, at only 13 years of age, he attempted to again enlist in the Union Army. After his father's initial refusal, he consented to let him go after Robinson told him that if he didn't let him enlist, he would just run away again and do it any way.

Upon enlistment, Robinson B. Murphy served with Company, A of the 127th Illinois Volunteer Infantry. The 127th fought in battles throughout the South during the Civil War. In January 1864, Murphy was appointed orderly to General J.A. Lightburn. At the Battle of Atlanta in July 1865 Murphy distinguished himself by voluntarily leading two regiments of reinforcements to the line of battle as Union forces were in danger of being overrun. Murphy was charged with bringing Tennessee volunteers to the front and while leading them back his horse was shot out from beneath him whereby he mounted another horse to ensure that the Union line was saved.

For his gallantry at age 15, Robinson B. Murphy was awarded the Congressional Medal of Honor. He is the youngest man to awarded the Medal of Honor and the only person from Kendall County to receive such an award.

Murphy served with 127th Infantry until the unit was disbanded in 1865. Murphy lived to the age of 85 and is buried in Arlington National Cemetery.