"From the many, one" may best describe Col. John T. Wilder's Lightning Brigade. The unit was made up of "citizen soldiers" from the farms of Indiana and Illinois. The brigade was unique because it was created as a unit that could move with the speed of cavalry but fight with the power of infantry.
This new concept was tested during the long days of fighting at the battle of Chickamauga where Wilder's Brigade saved the Union Army from almost certain destruction on two occasions. The first time was on September 18, 1863, at Alexander's Bridge. There the 17th Indiana, the 98th Illinois and two sections of Lilly's Battery along with Minty's Cavalry made a valiant stand to hold off an entire Confederate Army Corps. Their action prevented a Confederate victory on the first day and avoided a total rout of the Union Army. Two days later the unit saved the Union forces during the last day of battle. While the rest of the right flank was fleeing to Chattanooga, the Lightning Brigade repulsed the charges of an entire Confederate infantry division, and then counter-attacked the Rebels. Due to the brigade's performance, Gen. George H. Thomas was able to make a rock-like stand to save the Union Army. From that day forward, General Thomas would be known as "The Rock of Chicamauga."
As a mounted infantry unit, Wilder's Brigade was recognized for its swiftness and endurance that revolutionized military tactics and caused it to become known as the Lighting Brigade. The units that comprised the brigade were the 17th and 72nd Indiana Infantry Regiment, the 9th and 123rd Illinois Infantry Regiments, and the 18th Indiana Battery of Light Artillery that was commanded by Capt. Eli Lilly of Indianapolis.