Soldiers from Cumberland County's leading militia cavalry unit, the Big Spring Adamantine Guards, became Company H of the Union Army's 3d Penna. Cavalry and served in the Civil War from 1861 to 1864. Company H fought in major engagements including Antietam, Chancellorsville, and Gettysburg, and during that period approximately 130 local men served in the company. When most of these still-amateur soldiers left the Newville CVRR station on August 8, 1861, they wore a varied assortment of military hats, caps, coats, blouses, and immense spurs. The unit took its name from Big Spring Creek, a spring-fed stream rising about three miles south of Newville at Springfield Rd. and flowing north through Newville before emptying into Conodoguinet Creek, while adamantine came from the Greek adamantinos, meaning hard or unyielding, like a diamond. Captain William E. Miller, the ranking officer of Company H during the Battle of Gettysburg, received the Medal of Honor for bravery and initiative on July 3, 1863, after leading a charge against the enemy's flank without orders, checking the attack, and cutting off and dispersing the rear of the column. After the war he worked in the hardware business in Carlisle, was elected to the Pennsylvania State Senate in 1898, died in 1919, and was buried in Gettysburg National Cemetery. William Baughman, born in 1829 in Newtown Twp., helped recruit Company H, served as a lieutenant in it and later as a captain in Company E of the 3rd Penna. Cavalry, then returned home after three years and six months of service to build a successful agricultural implement business in Shippensburg. On the third day of fighting at Gettysburg, the Adamantine Guards played a critical role in hard, close combat in East Cavalry Field as they cut through the Confederate left flank amid intense slaughter among men and horses.