40th Infantry Regiment completed its organization in May, 1861. Its members were recruited in Northumberland, Richmond, and Lancaster counties. After serving in the Aquia District, the unit was assigned to General Field's, Heth's, and H.H. Walker's Brigade, Army of Northern Virginia. It participated in the campaigns of the army from the Seven Days' Battles to Cold Harbor, then was involved in the Petersburg siege north of the James River and the Appomattox Campaign. It sustained 180 casualties during the Seven Days' Battles which was about half its effective force. The unit lost 4 wounded at Cedar Mountain, had 14 killed and 73 wounded at Chancellorsville, and of the 253 engaged at Gettysburg more than twenty percent were disabled. Many were captured at Sayler's Creek and only 7 men were included in the surrender on April 9, 1865. Field officers were Colonel John M. Brockenbrough; Lieutenant Colonels Fleet W. Cox, Arthur S. Cunningham, and Henry H. Walker; and Majors Edward T. Stakes and William T. Taliaferro.